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Since other sessions aren't allowed to look into a temporary table of our own session, we do not need to worry about the global xmin horizon when setting the vacuum XID cutoff. Indeed, if we're not inside a transaction block, we may set oldestXmin to be the next XID, because there cannot be any in-doubt tuples in a temp table, nor any tuples that are dead but still visible to some snapshot of our transaction. (VACUUM, of course, is never inside a transaction block; but we need to test that because CLUSTER shares the same code.) This approach allows us to always clean out a temp table completely during VACUUM, independently of concurrent activity. Aside from being useful in its own right, that simplifies building reproducible test cases. Discussion: https://postgr.es/m/3490536.1598629609@sss.pgh.pa.us
3699 lines
116 KiB
C
3699 lines
116 KiB
C
/*-------------------------------------------------------------------------
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*
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* vacuumlazy.c
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* Concurrent ("lazy") vacuuming.
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*
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*
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* The major space usage for LAZY VACUUM is storage for the array of dead tuple
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* TIDs. We want to ensure we can vacuum even the very largest relations with
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* finite memory space usage. To do that, we set upper bounds on the number of
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* tuples we will keep track of at once.
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*
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* We are willing to use at most maintenance_work_mem (or perhaps
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* autovacuum_work_mem) memory space to keep track of dead tuples. We
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* initially allocate an array of TIDs of that size, with an upper limit that
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* depends on table size (this limit ensures we don't allocate a huge area
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* uselessly for vacuuming small tables). If the array threatens to overflow,
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* we suspend the heap scan phase and perform a pass of index cleanup and page
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* compaction, then resume the heap scan with an empty TID array.
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*
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* If we're processing a table with no indexes, we can just vacuum each page
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* as we go; there's no need to save up multiple tuples to minimize the number
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* of index scans performed. So we don't use maintenance_work_mem memory for
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* the TID array, just enough to hold as many heap tuples as fit on one page.
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*
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* Lazy vacuum supports parallel execution with parallel worker processes. In
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* a parallel vacuum, we perform both index vacuum and index cleanup with
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* parallel worker processes. Individual indexes are processed by one vacuum
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* process. At the beginning of a lazy vacuum (at lazy_scan_heap) we prepare
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* the parallel context and initialize the DSM segment that contains shared
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* information as well as the memory space for storing dead tuples. When
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* starting either index vacuum or index cleanup, we launch parallel worker
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* processes. Once all indexes are processed the parallel worker processes
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* exit. After that, the leader process re-initializes the parallel context
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* so that it can use the same DSM for multiple passes of index vacuum and
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* for performing index cleanup. For updating the index statistics, we need
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* to update the system table and since updates are not allowed during
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* parallel mode we update the index statistics after exiting from the
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* parallel mode.
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*
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* Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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*
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* IDENTIFICATION
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* src/backend/access/heap/vacuumlazy.c
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include <math.h>
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#include "access/amapi.h"
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#include "access/genam.h"
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#include "access/heapam.h"
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#include "access/heapam_xlog.h"
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#include "access/htup_details.h"
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#include "access/multixact.h"
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#include "access/parallel.h"
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#include "access/transam.h"
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#include "access/visibilitymap.h"
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#include "access/xact.h"
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#include "access/xlog.h"
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#include "catalog/storage.h"
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#include "commands/dbcommands.h"
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#include "commands/progress.h"
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#include "commands/vacuum.h"
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#include "executor/instrument.h"
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#include "miscadmin.h"
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#include "optimizer/paths.h"
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#include "pgstat.h"
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#include "portability/instr_time.h"
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#include "postmaster/autovacuum.h"
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#include "storage/bufmgr.h"
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#include "storage/freespace.h"
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#include "storage/lmgr.h"
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#include "tcop/tcopprot.h"
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#include "utils/lsyscache.h"
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#include "utils/memutils.h"
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#include "utils/pg_rusage.h"
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#include "utils/timestamp.h"
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/*
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* Space/time tradeoff parameters: do these need to be user-tunable?
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*
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* To consider truncating the relation, we want there to be at least
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* REL_TRUNCATE_MINIMUM or (relsize / REL_TRUNCATE_FRACTION) (whichever
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* is less) potentially-freeable pages.
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*/
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#define REL_TRUNCATE_MINIMUM 1000
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#define REL_TRUNCATE_FRACTION 16
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/*
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* Timing parameters for truncate locking heuristics.
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*
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* These were not exposed as user tunable GUC values because it didn't seem
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* that the potential for improvement was great enough to merit the cost of
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* supporting them.
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*/
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#define VACUUM_TRUNCATE_LOCK_CHECK_INTERVAL 20 /* ms */
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#define VACUUM_TRUNCATE_LOCK_WAIT_INTERVAL 50 /* ms */
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#define VACUUM_TRUNCATE_LOCK_TIMEOUT 5000 /* ms */
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/*
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* When a table has no indexes, vacuum the FSM after every 8GB, approximately
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* (it won't be exact because we only vacuum FSM after processing a heap page
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* that has some removable tuples). When there are indexes, this is ignored,
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* and we vacuum FSM after each index/heap cleaning pass.
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*/
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#define VACUUM_FSM_EVERY_PAGES \
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((BlockNumber) (((uint64) 8 * 1024 * 1024 * 1024) / BLCKSZ))
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/*
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* Guesstimation of number of dead tuples per page. This is used to
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* provide an upper limit to memory allocated when vacuuming small
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* tables.
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*/
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#define LAZY_ALLOC_TUPLES MaxHeapTuplesPerPage
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/*
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* Before we consider skipping a page that's marked as clean in
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* visibility map, we must've seen at least this many clean pages.
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*/
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#define SKIP_PAGES_THRESHOLD ((BlockNumber) 32)
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/*
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* Size of the prefetch window for lazy vacuum backwards truncation scan.
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* Needs to be a power of 2.
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*/
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#define PREFETCH_SIZE ((BlockNumber) 32)
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/*
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* DSM keys for parallel vacuum. Unlike other parallel execution code, since
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* we don't need to worry about DSM keys conflicting with plan_node_id we can
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* use small integers.
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*/
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#define PARALLEL_VACUUM_KEY_SHARED 1
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#define PARALLEL_VACUUM_KEY_DEAD_TUPLES 2
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#define PARALLEL_VACUUM_KEY_QUERY_TEXT 3
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#define PARALLEL_VACUUM_KEY_BUFFER_USAGE 4
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#define PARALLEL_VACUUM_KEY_WAL_USAGE 5
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/*
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* Macro to check if we are in a parallel vacuum. If true, we are in the
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* parallel mode and the DSM segment is initialized.
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*/
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#define ParallelVacuumIsActive(lps) PointerIsValid(lps)
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/* Phases of vacuum during which we report error context. */
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typedef enum
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{
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VACUUM_ERRCB_PHASE_UNKNOWN,
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VACUUM_ERRCB_PHASE_SCAN_HEAP,
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VACUUM_ERRCB_PHASE_VACUUM_INDEX,
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VACUUM_ERRCB_PHASE_VACUUM_HEAP,
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VACUUM_ERRCB_PHASE_INDEX_CLEANUP,
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VACUUM_ERRCB_PHASE_TRUNCATE
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} VacErrPhase;
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/*
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* LVDeadTuples stores the dead tuple TIDs collected during the heap scan.
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* This is allocated in the DSM segment in parallel mode and in local memory
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* in non-parallel mode.
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*/
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typedef struct LVDeadTuples
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{
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int max_tuples; /* # slots allocated in array */
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int num_tuples; /* current # of entries */
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/* List of TIDs of tuples we intend to delete */
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/* NB: this list is ordered by TID address */
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ItemPointerData itemptrs[FLEXIBLE_ARRAY_MEMBER]; /* array of
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* ItemPointerData */
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} LVDeadTuples;
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/* The dead tuple space consists of LVDeadTuples and dead tuple TIDs */
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#define SizeOfDeadTuples(cnt) \
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add_size(offsetof(LVDeadTuples, itemptrs), \
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mul_size(sizeof(ItemPointerData), cnt))
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#define MAXDEADTUPLES(max_size) \
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(((max_size) - offsetof(LVDeadTuples, itemptrs)) / sizeof(ItemPointerData))
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/*
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* Shared information among parallel workers. So this is allocated in the DSM
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* segment.
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*/
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typedef struct LVShared
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{
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/*
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* Target table relid and log level. These fields are not modified during
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* the lazy vacuum.
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*/
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Oid relid;
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int elevel;
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/*
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* An indication for vacuum workers to perform either index vacuum or
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* index cleanup. first_time is true only if for_cleanup is true and
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* bulk-deletion is not performed yet.
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*/
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bool for_cleanup;
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bool first_time;
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/*
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* Fields for both index vacuum and cleanup.
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*
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* reltuples is the total number of input heap tuples. We set either old
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* live tuples in the index vacuum case or the new live tuples in the
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* index cleanup case.
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*
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* estimated_count is true if reltuples is an estimated value. (Note that
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* reltuples could be -1 in this case, indicating we have no idea.)
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*/
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double reltuples;
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bool estimated_count;
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/*
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* In single process lazy vacuum we could consume more memory during index
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* vacuuming or cleanup apart from the memory for heap scanning. In
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* parallel vacuum, since individual vacuum workers can consume memory
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* equal to maintenance_work_mem, the new maintenance_work_mem for each
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* worker is set such that the parallel operation doesn't consume more
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* memory than single process lazy vacuum.
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*/
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int maintenance_work_mem_worker;
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/*
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* Shared vacuum cost balance. During parallel vacuum,
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* VacuumSharedCostBalance points to this value and it accumulates the
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* balance of each parallel vacuum worker.
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*/
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pg_atomic_uint32 cost_balance;
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/*
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* Number of active parallel workers. This is used for computing the
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* minimum threshold of the vacuum cost balance before a worker sleeps for
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* cost-based delay.
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*/
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pg_atomic_uint32 active_nworkers;
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/*
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* Variables to control parallel vacuum. We have a bitmap to indicate
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* which index has stats in shared memory. The set bit in the map
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* indicates that the particular index supports a parallel vacuum.
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*/
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pg_atomic_uint32 idx; /* counter for vacuuming and clean up */
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uint32 offset; /* sizeof header incl. bitmap */
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bits8 bitmap[FLEXIBLE_ARRAY_MEMBER]; /* bit map of NULLs */
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/* Shared index statistics data follows at end of struct */
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} LVShared;
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#define SizeOfLVShared (offsetof(LVShared, bitmap) + sizeof(bits8))
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#define GetSharedIndStats(s) \
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((LVSharedIndStats *)((char *)(s) + ((LVShared *)(s))->offset))
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#define IndStatsIsNull(s, i) \
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(!(((LVShared *)(s))->bitmap[(i) >> 3] & (1 << ((i) & 0x07))))
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/*
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* Struct for an index bulk-deletion statistic used for parallel vacuum. This
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* is allocated in the DSM segment.
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*/
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typedef struct LVSharedIndStats
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{
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bool updated; /* are the stats updated? */
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IndexBulkDeleteResult stats;
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} LVSharedIndStats;
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/* Struct for maintaining a parallel vacuum state. */
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typedef struct LVParallelState
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{
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ParallelContext *pcxt;
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/* Shared information among parallel vacuum workers */
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LVShared *lvshared;
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/* Points to buffer usage area in DSM */
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BufferUsage *buffer_usage;
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/* Points to WAL usage area in DSM */
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WalUsage *wal_usage;
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/*
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* The number of indexes that support parallel index bulk-deletion and
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* parallel index cleanup respectively.
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*/
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int nindexes_parallel_bulkdel;
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int nindexes_parallel_cleanup;
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int nindexes_parallel_condcleanup;
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} LVParallelState;
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typedef struct LVRelStats
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{
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char *relnamespace;
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char *relname;
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/* useindex = true means two-pass strategy; false means one-pass */
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bool useindex;
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/* Overall statistics about rel */
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BlockNumber old_rel_pages; /* previous value of pg_class.relpages */
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BlockNumber rel_pages; /* total number of pages */
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BlockNumber scanned_pages; /* number of pages we examined */
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BlockNumber pinskipped_pages; /* # of pages we skipped due to a pin */
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BlockNumber frozenskipped_pages; /* # of frozen pages we skipped */
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BlockNumber tupcount_pages; /* pages whose tuples we counted */
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double old_live_tuples; /* previous value of pg_class.reltuples */
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double new_rel_tuples; /* new estimated total # of tuples */
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double new_live_tuples; /* new estimated total # of live tuples */
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double new_dead_tuples; /* new estimated total # of dead tuples */
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BlockNumber pages_removed;
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double tuples_deleted;
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BlockNumber nonempty_pages; /* actually, last nonempty page + 1 */
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LVDeadTuples *dead_tuples;
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int num_index_scans;
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TransactionId latestRemovedXid;
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bool lock_waiter_detected;
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/* Used for error callback */
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char *indname;
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BlockNumber blkno; /* used only for heap operations */
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OffsetNumber offnum; /* used only for heap operations */
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VacErrPhase phase;
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} LVRelStats;
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/* Struct for saving and restoring vacuum error information. */
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typedef struct LVSavedErrInfo
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{
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BlockNumber blkno;
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OffsetNumber offnum;
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VacErrPhase phase;
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} LVSavedErrInfo;
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/* A few variables that don't seem worth passing around as parameters */
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static int elevel = -1;
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static TransactionId OldestXmin;
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static TransactionId FreezeLimit;
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static MultiXactId MultiXactCutoff;
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static BufferAccessStrategy vac_strategy;
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/* non-export function prototypes */
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static void lazy_scan_heap(Relation onerel, VacuumParams *params,
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LVRelStats *vacrelstats, Relation *Irel, int nindexes,
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bool aggressive);
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static void lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats);
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static bool lazy_check_needs_freeze(Buffer buf, bool *hastup,
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LVRelStats *vacrelstats);
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static void lazy_vacuum_all_indexes(Relation onerel, Relation *Irel,
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IndexBulkDeleteResult **stats,
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LVRelStats *vacrelstats, LVParallelState *lps,
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int nindexes);
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static void lazy_vacuum_index(Relation indrel, IndexBulkDeleteResult **stats,
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LVDeadTuples *dead_tuples, double reltuples, LVRelStats *vacrelstats);
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static void lazy_cleanup_index(Relation indrel,
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IndexBulkDeleteResult **stats,
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double reltuples, bool estimated_count, LVRelStats *vacrelstats);
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static int lazy_vacuum_page(Relation onerel, BlockNumber blkno, Buffer buffer,
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int tupindex, LVRelStats *vacrelstats, Buffer *vmbuffer);
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static bool should_attempt_truncation(VacuumParams *params,
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LVRelStats *vacrelstats);
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static void lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats);
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static BlockNumber count_nondeletable_pages(Relation onerel,
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LVRelStats *vacrelstats);
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static void lazy_space_alloc(LVRelStats *vacrelstats, BlockNumber relblocks);
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static void lazy_record_dead_tuple(LVDeadTuples *dead_tuples,
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ItemPointer itemptr);
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static bool lazy_tid_reaped(ItemPointer itemptr, void *state);
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static int vac_cmp_itemptr(const void *left, const void *right);
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static bool heap_page_is_all_visible(Relation rel, Buffer buf,
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LVRelStats *vacrelstats,
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TransactionId *visibility_cutoff_xid, bool *all_frozen);
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static void lazy_parallel_vacuum_indexes(Relation *Irel, IndexBulkDeleteResult **stats,
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LVRelStats *vacrelstats, LVParallelState *lps,
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int nindexes);
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static void parallel_vacuum_index(Relation *Irel, IndexBulkDeleteResult **stats,
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LVShared *lvshared, LVDeadTuples *dead_tuples,
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int nindexes, LVRelStats *vacrelstats);
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static void vacuum_indexes_leader(Relation *Irel, IndexBulkDeleteResult **stats,
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LVRelStats *vacrelstats, LVParallelState *lps,
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int nindexes);
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static void vacuum_one_index(Relation indrel, IndexBulkDeleteResult **stats,
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LVShared *lvshared, LVSharedIndStats *shared_indstats,
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LVDeadTuples *dead_tuples, LVRelStats *vacrelstats);
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static void lazy_cleanup_all_indexes(Relation *Irel, IndexBulkDeleteResult **stats,
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LVRelStats *vacrelstats, LVParallelState *lps,
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int nindexes);
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static long compute_max_dead_tuples(BlockNumber relblocks, bool hasindex);
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static int compute_parallel_vacuum_workers(Relation *Irel, int nindexes, int nrequested,
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bool *can_parallel_vacuum);
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static void prepare_index_statistics(LVShared *lvshared, bool *can_parallel_vacuum,
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int nindexes);
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static void update_index_statistics(Relation *Irel, IndexBulkDeleteResult **stats,
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int nindexes);
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static LVParallelState *begin_parallel_vacuum(Oid relid, Relation *Irel,
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LVRelStats *vacrelstats, BlockNumber nblocks,
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int nindexes, int nrequested);
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static void end_parallel_vacuum(IndexBulkDeleteResult **stats,
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LVParallelState *lps, int nindexes);
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static LVSharedIndStats *get_indstats(LVShared *lvshared, int n);
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static bool skip_parallel_vacuum_index(Relation indrel, LVShared *lvshared);
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static void vacuum_error_callback(void *arg);
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static void update_vacuum_error_info(LVRelStats *errinfo, LVSavedErrInfo *saved_err_info,
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int phase, BlockNumber blkno,
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OffsetNumber offnum);
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static void restore_vacuum_error_info(LVRelStats *errinfo, const LVSavedErrInfo *saved_err_info);
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|
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/*
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* heap_vacuum_rel() -- perform VACUUM for one heap relation
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*
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* This routine vacuums a single heap, cleans out its indexes, and
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* updates its relpages and reltuples statistics.
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*
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* At entry, we have already established a transaction and opened
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* and locked the relation.
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*/
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void
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heap_vacuum_rel(Relation onerel, VacuumParams *params,
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BufferAccessStrategy bstrategy)
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{
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LVRelStats *vacrelstats;
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Relation *Irel;
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int nindexes;
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PGRUsage ru0;
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TimestampTz starttime = 0;
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WalUsage walusage_start = pgWalUsage;
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WalUsage walusage = {0, 0, 0};
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long secs;
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int usecs;
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double read_rate,
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write_rate;
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bool aggressive; /* should we scan all unfrozen pages? */
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bool scanned_all_unfrozen; /* actually scanned all such pages? */
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TransactionId xidFullScanLimit;
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MultiXactId mxactFullScanLimit;
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BlockNumber new_rel_pages;
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BlockNumber new_rel_allvisible;
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double new_live_tuples;
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TransactionId new_frozen_xid;
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MultiXactId new_min_multi;
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ErrorContextCallback errcallback;
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Assert(params != NULL);
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Assert(params->index_cleanup != VACOPT_TERNARY_DEFAULT);
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Assert(params->truncate != VACOPT_TERNARY_DEFAULT);
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/* not every AM requires these to be valid, but heap does */
|
|
Assert(TransactionIdIsNormal(onerel->rd_rel->relfrozenxid));
|
|
Assert(MultiXactIdIsValid(onerel->rd_rel->relminmxid));
|
|
|
|
/* measure elapsed time iff autovacuum logging requires it */
|
|
if (IsAutoVacuumWorkerProcess() && params->log_min_duration >= 0)
|
|
{
|
|
pg_rusage_init(&ru0);
|
|
starttime = GetCurrentTimestamp();
|
|
}
|
|
|
|
if (params->options & VACOPT_VERBOSE)
|
|
elevel = INFO;
|
|
else
|
|
elevel = DEBUG2;
|
|
|
|
pgstat_progress_start_command(PROGRESS_COMMAND_VACUUM,
|
|
RelationGetRelid(onerel));
|
|
|
|
vac_strategy = bstrategy;
|
|
|
|
vacuum_set_xid_limits(onerel,
|
|
params->freeze_min_age,
|
|
params->freeze_table_age,
|
|
params->multixact_freeze_min_age,
|
|
params->multixact_freeze_table_age,
|
|
true, /* we must be a top-level command */
|
|
&OldestXmin, &FreezeLimit, &xidFullScanLimit,
|
|
&MultiXactCutoff, &mxactFullScanLimit);
|
|
|
|
/*
|
|
* We request an aggressive scan if the table's frozen Xid is now older
|
|
* than or equal to the requested Xid full-table scan limit; or if the
|
|
* table's minimum MultiXactId is older than or equal to the requested
|
|
* mxid full-table scan limit; or if DISABLE_PAGE_SKIPPING was specified.
|
|
*/
|
|
aggressive = TransactionIdPrecedesOrEquals(onerel->rd_rel->relfrozenxid,
|
|
xidFullScanLimit);
|
|
aggressive |= MultiXactIdPrecedesOrEquals(onerel->rd_rel->relminmxid,
|
|
mxactFullScanLimit);
|
|
if (params->options & VACOPT_DISABLE_PAGE_SKIPPING)
|
|
aggressive = true;
|
|
|
|
vacrelstats = (LVRelStats *) palloc0(sizeof(LVRelStats));
|
|
|
|
vacrelstats->relnamespace = get_namespace_name(RelationGetNamespace(onerel));
|
|
vacrelstats->relname = pstrdup(RelationGetRelationName(onerel));
|
|
vacrelstats->indname = NULL;
|
|
vacrelstats->phase = VACUUM_ERRCB_PHASE_UNKNOWN;
|
|
vacrelstats->old_rel_pages = onerel->rd_rel->relpages;
|
|
vacrelstats->old_live_tuples = onerel->rd_rel->reltuples;
|
|
vacrelstats->num_index_scans = 0;
|
|
vacrelstats->pages_removed = 0;
|
|
vacrelstats->lock_waiter_detected = false;
|
|
|
|
/* Open all indexes of the relation */
|
|
vac_open_indexes(onerel, RowExclusiveLock, &nindexes, &Irel);
|
|
vacrelstats->useindex = (nindexes > 0 &&
|
|
params->index_cleanup == VACOPT_TERNARY_ENABLED);
|
|
|
|
/*
|
|
* Setup error traceback support for ereport(). The idea is to set up an
|
|
* error context callback to display additional information on any error
|
|
* during a vacuum. During different phases of vacuum (heap scan, heap
|
|
* vacuum, index vacuum, index clean up, heap truncate), we update the
|
|
* error context callback to display appropriate information.
|
|
*
|
|
* Note that the index vacuum and heap vacuum phases may be called
|
|
* multiple times in the middle of the heap scan phase. So the old phase
|
|
* information is restored at the end of those phases.
|
|
*/
|
|
errcallback.callback = vacuum_error_callback;
|
|
errcallback.arg = vacrelstats;
|
|
errcallback.previous = error_context_stack;
|
|
error_context_stack = &errcallback;
|
|
|
|
/* Do the vacuuming */
|
|
lazy_scan_heap(onerel, params, vacrelstats, Irel, nindexes, aggressive);
|
|
|
|
/* Done with indexes */
|
|
vac_close_indexes(nindexes, Irel, NoLock);
|
|
|
|
/*
|
|
* Compute whether we actually scanned the all unfrozen pages. If we did,
|
|
* we can adjust relfrozenxid and relminmxid.
|
|
*
|
|
* NB: We need to check this before truncating the relation, because that
|
|
* will change ->rel_pages.
|
|
*/
|
|
if ((vacrelstats->scanned_pages + vacrelstats->frozenskipped_pages)
|
|
< vacrelstats->rel_pages)
|
|
{
|
|
Assert(!aggressive);
|
|
scanned_all_unfrozen = false;
|
|
}
|
|
else
|
|
scanned_all_unfrozen = true;
|
|
|
|
/*
|
|
* Optionally truncate the relation.
|
|
*/
|
|
if (should_attempt_truncation(params, vacrelstats))
|
|
{
|
|
/*
|
|
* Update error traceback information. This is the last phase during
|
|
* which we add context information to errors, so we don't need to
|
|
* revert to the previous phase.
|
|
*/
|
|
update_vacuum_error_info(vacrelstats, NULL, VACUUM_ERRCB_PHASE_TRUNCATE,
|
|
vacrelstats->nonempty_pages,
|
|
InvalidOffsetNumber);
|
|
lazy_truncate_heap(onerel, vacrelstats);
|
|
}
|
|
|
|
/* Pop the error context stack */
|
|
error_context_stack = errcallback.previous;
|
|
|
|
/* Report that we are now doing final cleanup */
|
|
pgstat_progress_update_param(PROGRESS_VACUUM_PHASE,
|
|
PROGRESS_VACUUM_PHASE_FINAL_CLEANUP);
|
|
|
|
/*
|
|
* Update statistics in pg_class.
|
|
*
|
|
* In principle new_live_tuples could be -1 indicating that we (still)
|
|
* don't know the tuple count. In practice that probably can't happen,
|
|
* since we'd surely have scanned some pages if the table is new and
|
|
* nonempty.
|
|
*
|
|
* For safety, clamp relallvisible to be not more than what we're setting
|
|
* relpages to.
|
|
*
|
|
* Also, don't change relfrozenxid/relminmxid if we skipped any pages,
|
|
* since then we don't know for certain that all tuples have a newer xmin.
|
|
*/
|
|
new_rel_pages = vacrelstats->rel_pages;
|
|
new_live_tuples = vacrelstats->new_live_tuples;
|
|
|
|
visibilitymap_count(onerel, &new_rel_allvisible, NULL);
|
|
if (new_rel_allvisible > new_rel_pages)
|
|
new_rel_allvisible = new_rel_pages;
|
|
|
|
new_frozen_xid = scanned_all_unfrozen ? FreezeLimit : InvalidTransactionId;
|
|
new_min_multi = scanned_all_unfrozen ? MultiXactCutoff : InvalidMultiXactId;
|
|
|
|
vac_update_relstats(onerel,
|
|
new_rel_pages,
|
|
new_live_tuples,
|
|
new_rel_allvisible,
|
|
nindexes > 0,
|
|
new_frozen_xid,
|
|
new_min_multi,
|
|
false);
|
|
|
|
/* report results to the stats collector, too */
|
|
pgstat_report_vacuum(RelationGetRelid(onerel),
|
|
onerel->rd_rel->relisshared,
|
|
Max(new_live_tuples, 0),
|
|
vacrelstats->new_dead_tuples);
|
|
pgstat_progress_end_command();
|
|
|
|
/* and log the action if appropriate */
|
|
if (IsAutoVacuumWorkerProcess() && params->log_min_duration >= 0)
|
|
{
|
|
TimestampTz endtime = GetCurrentTimestamp();
|
|
|
|
if (params->log_min_duration == 0 ||
|
|
TimestampDifferenceExceeds(starttime, endtime,
|
|
params->log_min_duration))
|
|
{
|
|
StringInfoData buf;
|
|
char *msgfmt;
|
|
|
|
TimestampDifference(starttime, endtime, &secs, &usecs);
|
|
|
|
memset(&walusage, 0, sizeof(WalUsage));
|
|
WalUsageAccumDiff(&walusage, &pgWalUsage, &walusage_start);
|
|
|
|
read_rate = 0;
|
|
write_rate = 0;
|
|
if ((secs > 0) || (usecs > 0))
|
|
{
|
|
read_rate = (double) BLCKSZ * VacuumPageMiss / (1024 * 1024) /
|
|
(secs + usecs / 1000000.0);
|
|
write_rate = (double) BLCKSZ * VacuumPageDirty / (1024 * 1024) /
|
|
(secs + usecs / 1000000.0);
|
|
}
|
|
|
|
/*
|
|
* This is pretty messy, but we split it up so that we can skip
|
|
* emitting individual parts of the message when not applicable.
|
|
*/
|
|
initStringInfo(&buf);
|
|
if (params->is_wraparound)
|
|
{
|
|
if (aggressive)
|
|
msgfmt = _("automatic aggressive vacuum to prevent wraparound of table \"%s.%s.%s\": index scans: %d\n");
|
|
else
|
|
msgfmt = _("automatic vacuum to prevent wraparound of table \"%s.%s.%s\": index scans: %d\n");
|
|
}
|
|
else
|
|
{
|
|
if (aggressive)
|
|
msgfmt = _("automatic aggressive vacuum of table \"%s.%s.%s\": index scans: %d\n");
|
|
else
|
|
msgfmt = _("automatic vacuum of table \"%s.%s.%s\": index scans: %d\n");
|
|
}
|
|
appendStringInfo(&buf, msgfmt,
|
|
get_database_name(MyDatabaseId),
|
|
vacrelstats->relnamespace,
|
|
vacrelstats->relname,
|
|
vacrelstats->num_index_scans);
|
|
appendStringInfo(&buf, _("pages: %u removed, %u remain, %u skipped due to pins, %u skipped frozen\n"),
|
|
vacrelstats->pages_removed,
|
|
vacrelstats->rel_pages,
|
|
vacrelstats->pinskipped_pages,
|
|
vacrelstats->frozenskipped_pages);
|
|
appendStringInfo(&buf,
|
|
_("tuples: %.0f removed, %.0f remain, %.0f are dead but not yet removable, oldest xmin: %u\n"),
|
|
vacrelstats->tuples_deleted,
|
|
vacrelstats->new_rel_tuples,
|
|
vacrelstats->new_dead_tuples,
|
|
OldestXmin);
|
|
appendStringInfo(&buf,
|
|
_("buffer usage: %lld hits, %lld misses, %lld dirtied\n"),
|
|
(long long) VacuumPageHit,
|
|
(long long) VacuumPageMiss,
|
|
(long long) VacuumPageDirty);
|
|
appendStringInfo(&buf, _("avg read rate: %.3f MB/s, avg write rate: %.3f MB/s\n"),
|
|
read_rate, write_rate);
|
|
appendStringInfo(&buf, _("system usage: %s\n"), pg_rusage_show(&ru0));
|
|
appendStringInfo(&buf,
|
|
_("WAL usage: %ld records, %ld full page images, "
|
|
UINT64_FORMAT " bytes"),
|
|
walusage.wal_records,
|
|
walusage.wal_fpi,
|
|
walusage.wal_bytes);
|
|
|
|
ereport(LOG,
|
|
(errmsg_internal("%s", buf.data)));
|
|
pfree(buf.data);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* For Hot Standby we need to know the highest transaction id that will
|
|
* be removed by any change. VACUUM proceeds in a number of passes so
|
|
* we need to consider how each pass operates. The first phase runs
|
|
* heap_page_prune(), which can issue XLOG_HEAP2_CLEAN records as it
|
|
* progresses - these will have a latestRemovedXid on each record.
|
|
* In some cases this removes all of the tuples to be removed, though
|
|
* often we have dead tuples with index pointers so we must remember them
|
|
* for removal in phase 3. Index records for those rows are removed
|
|
* in phase 2 and index blocks do not have MVCC information attached.
|
|
* So before we can allow removal of any index tuples we need to issue
|
|
* a WAL record containing the latestRemovedXid of rows that will be
|
|
* removed in phase three. This allows recovery queries to block at the
|
|
* correct place, i.e. before phase two, rather than during phase three
|
|
* which would be after the rows have become inaccessible.
|
|
*/
|
|
static void
|
|
vacuum_log_cleanup_info(Relation rel, LVRelStats *vacrelstats)
|
|
{
|
|
/*
|
|
* Skip this for relations for which no WAL is to be written, or if we're
|
|
* not trying to support archive recovery.
|
|
*/
|
|
if (!RelationNeedsWAL(rel) || !XLogIsNeeded())
|
|
return;
|
|
|
|
/*
|
|
* No need to write the record at all unless it contains a valid value
|
|
*/
|
|
if (TransactionIdIsValid(vacrelstats->latestRemovedXid))
|
|
(void) log_heap_cleanup_info(rel->rd_node, vacrelstats->latestRemovedXid);
|
|
}
|
|
|
|
/*
|
|
* lazy_scan_heap() -- scan an open heap relation
|
|
*
|
|
* This routine prunes each page in the heap, which will among other
|
|
* things truncate dead tuples to dead line pointers, defragment the
|
|
* page, and set commit status bits (see heap_page_prune). It also builds
|
|
* lists of dead tuples and pages with free space, calculates statistics
|
|
* on the number of live tuples in the heap, and marks pages as
|
|
* all-visible if appropriate. When done, or when we run low on space for
|
|
* dead-tuple TIDs, invoke vacuuming of indexes and call lazy_vacuum_heap
|
|
* to reclaim dead line pointers.
|
|
*
|
|
* If the table has at least two indexes, we execute both index vacuum
|
|
* and index cleanup with parallel workers unless parallel vacuum is
|
|
* disabled. In a parallel vacuum, we enter parallel mode and then
|
|
* create both the parallel context and the DSM segment before starting
|
|
* heap scan so that we can record dead tuples to the DSM segment. All
|
|
* parallel workers are launched at beginning of index vacuuming and
|
|
* index cleanup and they exit once done with all indexes. At the end of
|
|
* this function we exit from parallel mode. Index bulk-deletion results
|
|
* are stored in the DSM segment and we update index statistics for all
|
|
* the indexes after exiting from parallel mode since writes are not
|
|
* allowed during parallel mode.
|
|
*
|
|
* If there are no indexes then we can reclaim line pointers on the fly;
|
|
* dead line pointers need only be retained until all index pointers that
|
|
* reference them have been killed.
|
|
*/
|
|
static void
|
|
lazy_scan_heap(Relation onerel, VacuumParams *params, LVRelStats *vacrelstats,
|
|
Relation *Irel, int nindexes, bool aggressive)
|
|
{
|
|
LVParallelState *lps = NULL;
|
|
LVDeadTuples *dead_tuples;
|
|
BlockNumber nblocks,
|
|
blkno;
|
|
HeapTupleData tuple;
|
|
TransactionId relfrozenxid = onerel->rd_rel->relfrozenxid;
|
|
TransactionId relminmxid = onerel->rd_rel->relminmxid;
|
|
BlockNumber empty_pages,
|
|
vacuumed_pages,
|
|
next_fsm_block_to_vacuum;
|
|
double num_tuples, /* total number of nonremovable tuples */
|
|
live_tuples, /* live tuples (reltuples estimate) */
|
|
tups_vacuumed, /* tuples cleaned up by vacuum */
|
|
nkeep, /* dead-but-not-removable tuples */
|
|
nunused; /* unused line pointers */
|
|
IndexBulkDeleteResult **indstats;
|
|
int i;
|
|
PGRUsage ru0;
|
|
Buffer vmbuffer = InvalidBuffer;
|
|
BlockNumber next_unskippable_block;
|
|
bool skipping_blocks;
|
|
xl_heap_freeze_tuple *frozen;
|
|
StringInfoData buf;
|
|
const int initprog_index[] = {
|
|
PROGRESS_VACUUM_PHASE,
|
|
PROGRESS_VACUUM_TOTAL_HEAP_BLKS,
|
|
PROGRESS_VACUUM_MAX_DEAD_TUPLES
|
|
};
|
|
int64 initprog_val[3];
|
|
GlobalVisState *vistest;
|
|
|
|
pg_rusage_init(&ru0);
|
|
|
|
if (aggressive)
|
|
ereport(elevel,
|
|
(errmsg("aggressively vacuuming \"%s.%s\"",
|
|
vacrelstats->relnamespace,
|
|
vacrelstats->relname)));
|
|
else
|
|
ereport(elevel,
|
|
(errmsg("vacuuming \"%s.%s\"",
|
|
vacrelstats->relnamespace,
|
|
vacrelstats->relname)));
|
|
|
|
empty_pages = vacuumed_pages = 0;
|
|
next_fsm_block_to_vacuum = (BlockNumber) 0;
|
|
num_tuples = live_tuples = tups_vacuumed = nkeep = nunused = 0;
|
|
|
|
indstats = (IndexBulkDeleteResult **)
|
|
palloc0(nindexes * sizeof(IndexBulkDeleteResult *));
|
|
|
|
nblocks = RelationGetNumberOfBlocks(onerel);
|
|
vacrelstats->rel_pages = nblocks;
|
|
vacrelstats->scanned_pages = 0;
|
|
vacrelstats->tupcount_pages = 0;
|
|
vacrelstats->nonempty_pages = 0;
|
|
vacrelstats->latestRemovedXid = InvalidTransactionId;
|
|
|
|
vistest = GlobalVisTestFor(onerel);
|
|
|
|
/*
|
|
* Initialize state for a parallel vacuum. As of now, only one worker can
|
|
* be used for an index, so we invoke parallelism only if there are at
|
|
* least two indexes on a table.
|
|
*/
|
|
if (params->nworkers >= 0 && vacrelstats->useindex && nindexes > 1)
|
|
{
|
|
/*
|
|
* Since parallel workers cannot access data in temporary tables, we
|
|
* can't perform parallel vacuum on them.
|
|
*/
|
|
if (RelationUsesLocalBuffers(onerel))
|
|
{
|
|
/*
|
|
* Give warning only if the user explicitly tries to perform a
|
|
* parallel vacuum on the temporary table.
|
|
*/
|
|
if (params->nworkers > 0)
|
|
ereport(WARNING,
|
|
(errmsg("disabling parallel option of vacuum on \"%s\" --- cannot vacuum temporary tables in parallel",
|
|
vacrelstats->relname)));
|
|
}
|
|
else
|
|
lps = begin_parallel_vacuum(RelationGetRelid(onerel), Irel,
|
|
vacrelstats, nblocks, nindexes,
|
|
params->nworkers);
|
|
}
|
|
|
|
/*
|
|
* Allocate the space for dead tuples in case parallel vacuum is not
|
|
* initialized.
|
|
*/
|
|
if (!ParallelVacuumIsActive(lps))
|
|
lazy_space_alloc(vacrelstats, nblocks);
|
|
|
|
dead_tuples = vacrelstats->dead_tuples;
|
|
frozen = palloc(sizeof(xl_heap_freeze_tuple) * MaxHeapTuplesPerPage);
|
|
|
|
/* Report that we're scanning the heap, advertising total # of blocks */
|
|
initprog_val[0] = PROGRESS_VACUUM_PHASE_SCAN_HEAP;
|
|
initprog_val[1] = nblocks;
|
|
initprog_val[2] = dead_tuples->max_tuples;
|
|
pgstat_progress_update_multi_param(3, initprog_index, initprog_val);
|
|
|
|
/*
|
|
* Except when aggressive is set, we want to skip pages that are
|
|
* all-visible according to the visibility map, but only when we can skip
|
|
* at least SKIP_PAGES_THRESHOLD consecutive pages. Since we're reading
|
|
* sequentially, the OS should be doing readahead for us, so there's no
|
|
* gain in skipping a page now and then; that's likely to disable
|
|
* readahead and so be counterproductive. Also, skipping even a single
|
|
* page means that we can't update relfrozenxid, so we only want to do it
|
|
* if we can skip a goodly number of pages.
|
|
*
|
|
* When aggressive is set, we can't skip pages just because they are
|
|
* all-visible, but we can still skip pages that are all-frozen, since
|
|
* such pages do not need freezing and do not affect the value that we can
|
|
* safely set for relfrozenxid or relminmxid.
|
|
*
|
|
* Before entering the main loop, establish the invariant that
|
|
* next_unskippable_block is the next block number >= blkno that we can't
|
|
* skip based on the visibility map, either all-visible for a regular scan
|
|
* or all-frozen for an aggressive scan. We set it to nblocks if there's
|
|
* no such block. We also set up the skipping_blocks flag correctly at
|
|
* this stage.
|
|
*
|
|
* Note: The value returned by visibilitymap_get_status could be slightly
|
|
* out-of-date, since we make this test before reading the corresponding
|
|
* heap page or locking the buffer. This is OK. If we mistakenly think
|
|
* that the page is all-visible or all-frozen when in fact the flag's just
|
|
* been cleared, we might fail to vacuum the page. It's easy to see that
|
|
* skipping a page when aggressive is not set is not a very big deal; we
|
|
* might leave some dead tuples lying around, but the next vacuum will
|
|
* find them. But even when aggressive *is* set, it's still OK if we miss
|
|
* a page whose all-frozen marking has just been cleared. Any new XIDs
|
|
* just added to that page are necessarily newer than the GlobalXmin we
|
|
* computed, so they'll have no effect on the value to which we can safely
|
|
* set relfrozenxid. A similar argument applies for MXIDs and relminmxid.
|
|
*
|
|
* We will scan the table's last page, at least to the extent of
|
|
* determining whether it has tuples or not, even if it should be skipped
|
|
* according to the above rules; except when we've already determined that
|
|
* it's not worth trying to truncate the table. This avoids having
|
|
* lazy_truncate_heap() take access-exclusive lock on the table to attempt
|
|
* a truncation that just fails immediately because there are tuples in
|
|
* the last page. This is worth avoiding mainly because such a lock must
|
|
* be replayed on any hot standby, where it can be disruptive.
|
|
*/
|
|
next_unskippable_block = 0;
|
|
if ((params->options & VACOPT_DISABLE_PAGE_SKIPPING) == 0)
|
|
{
|
|
while (next_unskippable_block < nblocks)
|
|
{
|
|
uint8 vmstatus;
|
|
|
|
vmstatus = visibilitymap_get_status(onerel, next_unskippable_block,
|
|
&vmbuffer);
|
|
if (aggressive)
|
|
{
|
|
if ((vmstatus & VISIBILITYMAP_ALL_FROZEN) == 0)
|
|
break;
|
|
}
|
|
else
|
|
{
|
|
if ((vmstatus & VISIBILITYMAP_ALL_VISIBLE) == 0)
|
|
break;
|
|
}
|
|
vacuum_delay_point();
|
|
next_unskippable_block++;
|
|
}
|
|
}
|
|
|
|
if (next_unskippable_block >= SKIP_PAGES_THRESHOLD)
|
|
skipping_blocks = true;
|
|
else
|
|
skipping_blocks = false;
|
|
|
|
for (blkno = 0; blkno < nblocks; blkno++)
|
|
{
|
|
Buffer buf;
|
|
Page page;
|
|
OffsetNumber offnum,
|
|
maxoff;
|
|
bool tupgone,
|
|
hastup;
|
|
int prev_dead_count;
|
|
int nfrozen;
|
|
Size freespace;
|
|
bool all_visible_according_to_vm = false;
|
|
bool all_visible;
|
|
bool all_frozen = true; /* provided all_visible is also true */
|
|
bool has_dead_tuples;
|
|
TransactionId visibility_cutoff_xid = InvalidTransactionId;
|
|
|
|
/* see note above about forcing scanning of last page */
|
|
#define FORCE_CHECK_PAGE() \
|
|
(blkno == nblocks - 1 && should_attempt_truncation(params, vacrelstats))
|
|
|
|
pgstat_progress_update_param(PROGRESS_VACUUM_HEAP_BLKS_SCANNED, blkno);
|
|
|
|
update_vacuum_error_info(vacrelstats, NULL, VACUUM_ERRCB_PHASE_SCAN_HEAP,
|
|
blkno, InvalidOffsetNumber);
|
|
|
|
if (blkno == next_unskippable_block)
|
|
{
|
|
/* Time to advance next_unskippable_block */
|
|
next_unskippable_block++;
|
|
if ((params->options & VACOPT_DISABLE_PAGE_SKIPPING) == 0)
|
|
{
|
|
while (next_unskippable_block < nblocks)
|
|
{
|
|
uint8 vmskipflags;
|
|
|
|
vmskipflags = visibilitymap_get_status(onerel,
|
|
next_unskippable_block,
|
|
&vmbuffer);
|
|
if (aggressive)
|
|
{
|
|
if ((vmskipflags & VISIBILITYMAP_ALL_FROZEN) == 0)
|
|
break;
|
|
}
|
|
else
|
|
{
|
|
if ((vmskipflags & VISIBILITYMAP_ALL_VISIBLE) == 0)
|
|
break;
|
|
}
|
|
vacuum_delay_point();
|
|
next_unskippable_block++;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We know we can't skip the current block. But set up
|
|
* skipping_blocks to do the right thing at the following blocks.
|
|
*/
|
|
if (next_unskippable_block - blkno > SKIP_PAGES_THRESHOLD)
|
|
skipping_blocks = true;
|
|
else
|
|
skipping_blocks = false;
|
|
|
|
/*
|
|
* Normally, the fact that we can't skip this block must mean that
|
|
* it's not all-visible. But in an aggressive vacuum we know only
|
|
* that it's not all-frozen, so it might still be all-visible.
|
|
*/
|
|
if (aggressive && VM_ALL_VISIBLE(onerel, blkno, &vmbuffer))
|
|
all_visible_according_to_vm = true;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* The current block is potentially skippable; if we've seen a
|
|
* long enough run of skippable blocks to justify skipping it, and
|
|
* we're not forced to check it, then go ahead and skip.
|
|
* Otherwise, the page must be at least all-visible if not
|
|
* all-frozen, so we can set all_visible_according_to_vm = true.
|
|
*/
|
|
if (skipping_blocks && !FORCE_CHECK_PAGE())
|
|
{
|
|
/*
|
|
* Tricky, tricky. If this is in aggressive vacuum, the page
|
|
* must have been all-frozen at the time we checked whether it
|
|
* was skippable, but it might not be any more. We must be
|
|
* careful to count it as a skipped all-frozen page in that
|
|
* case, or else we'll think we can't update relfrozenxid and
|
|
* relminmxid. If it's not an aggressive vacuum, we don't
|
|
* know whether it was all-frozen, so we have to recheck; but
|
|
* in this case an approximate answer is OK.
|
|
*/
|
|
if (aggressive || VM_ALL_FROZEN(onerel, blkno, &vmbuffer))
|
|
vacrelstats->frozenskipped_pages++;
|
|
continue;
|
|
}
|
|
all_visible_according_to_vm = true;
|
|
}
|
|
|
|
vacuum_delay_point();
|
|
|
|
/*
|
|
* If we are close to overrunning the available space for dead-tuple
|
|
* TIDs, pause and do a cycle of vacuuming before we tackle this page.
|
|
*/
|
|
if ((dead_tuples->max_tuples - dead_tuples->num_tuples) < MaxHeapTuplesPerPage &&
|
|
dead_tuples->num_tuples > 0)
|
|
{
|
|
/*
|
|
* Before beginning index vacuuming, we release any pin we may
|
|
* hold on the visibility map page. This isn't necessary for
|
|
* correctness, but we do it anyway to avoid holding the pin
|
|
* across a lengthy, unrelated operation.
|
|
*/
|
|
if (BufferIsValid(vmbuffer))
|
|
{
|
|
ReleaseBuffer(vmbuffer);
|
|
vmbuffer = InvalidBuffer;
|
|
}
|
|
|
|
/* Work on all the indexes, then the heap */
|
|
lazy_vacuum_all_indexes(onerel, Irel, indstats,
|
|
vacrelstats, lps, nindexes);
|
|
|
|
/* Remove tuples from heap */
|
|
lazy_vacuum_heap(onerel, vacrelstats);
|
|
|
|
/*
|
|
* Forget the now-vacuumed tuples, and press on, but be careful
|
|
* not to reset latestRemovedXid since we want that value to be
|
|
* valid.
|
|
*/
|
|
dead_tuples->num_tuples = 0;
|
|
|
|
/*
|
|
* Vacuum the Free Space Map to make newly-freed space visible on
|
|
* upper-level FSM pages. Note we have not yet processed blkno.
|
|
*/
|
|
FreeSpaceMapVacuumRange(onerel, next_fsm_block_to_vacuum, blkno);
|
|
next_fsm_block_to_vacuum = blkno;
|
|
|
|
/* Report that we are once again scanning the heap */
|
|
pgstat_progress_update_param(PROGRESS_VACUUM_PHASE,
|
|
PROGRESS_VACUUM_PHASE_SCAN_HEAP);
|
|
}
|
|
|
|
/*
|
|
* Pin the visibility map page in case we need to mark the page
|
|
* all-visible. In most cases this will be very cheap, because we'll
|
|
* already have the correct page pinned anyway. However, it's
|
|
* possible that (a) next_unskippable_block is covered by a different
|
|
* VM page than the current block or (b) we released our pin and did a
|
|
* cycle of index vacuuming.
|
|
*
|
|
*/
|
|
visibilitymap_pin(onerel, blkno, &vmbuffer);
|
|
|
|
buf = ReadBufferExtended(onerel, MAIN_FORKNUM, blkno,
|
|
RBM_NORMAL, vac_strategy);
|
|
|
|
/* We need buffer cleanup lock so that we can prune HOT chains. */
|
|
if (!ConditionalLockBufferForCleanup(buf))
|
|
{
|
|
/*
|
|
* If we're not performing an aggressive scan to guard against XID
|
|
* wraparound, and we don't want to forcibly check the page, then
|
|
* it's OK to skip vacuuming pages we get a lock conflict on. They
|
|
* will be dealt with in some future vacuum.
|
|
*/
|
|
if (!aggressive && !FORCE_CHECK_PAGE())
|
|
{
|
|
ReleaseBuffer(buf);
|
|
vacrelstats->pinskipped_pages++;
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Read the page with share lock to see if any xids on it need to
|
|
* be frozen. If not we just skip the page, after updating our
|
|
* scan statistics. If there are some, we wait for cleanup lock.
|
|
*
|
|
* We could defer the lock request further by remembering the page
|
|
* and coming back to it later, or we could even register
|
|
* ourselves for multiple buffers and then service whichever one
|
|
* is received first. For now, this seems good enough.
|
|
*
|
|
* If we get here with aggressive false, then we're just forcibly
|
|
* checking the page, and so we don't want to insist on getting
|
|
* the lock; we only need to know if the page contains tuples, so
|
|
* that we can update nonempty_pages correctly. It's convenient
|
|
* to use lazy_check_needs_freeze() for both situations, though.
|
|
*/
|
|
LockBuffer(buf, BUFFER_LOCK_SHARE);
|
|
if (!lazy_check_needs_freeze(buf, &hastup, vacrelstats))
|
|
{
|
|
UnlockReleaseBuffer(buf);
|
|
vacrelstats->scanned_pages++;
|
|
vacrelstats->pinskipped_pages++;
|
|
if (hastup)
|
|
vacrelstats->nonempty_pages = blkno + 1;
|
|
continue;
|
|
}
|
|
if (!aggressive)
|
|
{
|
|
/*
|
|
* Here, we must not advance scanned_pages; that would amount
|
|
* to claiming that the page contains no freezable tuples.
|
|
*/
|
|
UnlockReleaseBuffer(buf);
|
|
vacrelstats->pinskipped_pages++;
|
|
if (hastup)
|
|
vacrelstats->nonempty_pages = blkno + 1;
|
|
continue;
|
|
}
|
|
LockBuffer(buf, BUFFER_LOCK_UNLOCK);
|
|
LockBufferForCleanup(buf);
|
|
/* drop through to normal processing */
|
|
}
|
|
|
|
vacrelstats->scanned_pages++;
|
|
vacrelstats->tupcount_pages++;
|
|
|
|
page = BufferGetPage(buf);
|
|
|
|
if (PageIsNew(page))
|
|
{
|
|
/*
|
|
* All-zeroes pages can be left over if either a backend extends
|
|
* the relation by a single page, but crashes before the newly
|
|
* initialized page has been written out, or when bulk-extending
|
|
* the relation (which creates a number of empty pages at the tail
|
|
* end of the relation, but enters them into the FSM).
|
|
*
|
|
* Note we do not enter the page into the visibilitymap. That has
|
|
* the downside that we repeatedly visit this page in subsequent
|
|
* vacuums, but otherwise we'll never not discover the space on a
|
|
* promoted standby. The harm of repeated checking ought to
|
|
* normally not be too bad - the space usually should be used at
|
|
* some point, otherwise there wouldn't be any regular vacuums.
|
|
*
|
|
* Make sure these pages are in the FSM, to ensure they can be
|
|
* reused. Do that by testing if there's any space recorded for
|
|
* the page. If not, enter it. We do so after releasing the lock
|
|
* on the heap page, the FSM is approximate, after all.
|
|
*/
|
|
UnlockReleaseBuffer(buf);
|
|
|
|
empty_pages++;
|
|
|
|
if (GetRecordedFreeSpace(onerel, blkno) == 0)
|
|
{
|
|
Size freespace;
|
|
|
|
freespace = BufferGetPageSize(buf) - SizeOfPageHeaderData;
|
|
RecordPageWithFreeSpace(onerel, blkno, freespace);
|
|
}
|
|
continue;
|
|
}
|
|
|
|
if (PageIsEmpty(page))
|
|
{
|
|
empty_pages++;
|
|
freespace = PageGetHeapFreeSpace(page);
|
|
|
|
/*
|
|
* Empty pages are always all-visible and all-frozen (note that
|
|
* the same is currently not true for new pages, see above).
|
|
*/
|
|
if (!PageIsAllVisible(page))
|
|
{
|
|
START_CRIT_SECTION();
|
|
|
|
/* mark buffer dirty before writing a WAL record */
|
|
MarkBufferDirty(buf);
|
|
|
|
/*
|
|
* It's possible that another backend has extended the heap,
|
|
* initialized the page, and then failed to WAL-log the page
|
|
* due to an ERROR. Since heap extension is not WAL-logged,
|
|
* recovery might try to replay our record setting the page
|
|
* all-visible and find that the page isn't initialized, which
|
|
* will cause a PANIC. To prevent that, check whether the
|
|
* page has been previously WAL-logged, and if not, do that
|
|
* now.
|
|
*/
|
|
if (RelationNeedsWAL(onerel) &&
|
|
PageGetLSN(page) == InvalidXLogRecPtr)
|
|
log_newpage_buffer(buf, true);
|
|
|
|
PageSetAllVisible(page);
|
|
visibilitymap_set(onerel, blkno, buf, InvalidXLogRecPtr,
|
|
vmbuffer, InvalidTransactionId,
|
|
VISIBILITYMAP_ALL_VISIBLE | VISIBILITYMAP_ALL_FROZEN);
|
|
END_CRIT_SECTION();
|
|
}
|
|
|
|
UnlockReleaseBuffer(buf);
|
|
RecordPageWithFreeSpace(onerel, blkno, freespace);
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Prune all HOT-update chains in this page.
|
|
*
|
|
* We count tuples removed by the pruning step as removed by VACUUM.
|
|
*/
|
|
tups_vacuumed += heap_page_prune(onerel, buf, vistest, false,
|
|
InvalidTransactionId, 0,
|
|
&vacrelstats->latestRemovedXid,
|
|
&vacrelstats->offnum);
|
|
|
|
/*
|
|
* Now scan the page to collect vacuumable items and check for tuples
|
|
* requiring freezing.
|
|
*/
|
|
all_visible = true;
|
|
has_dead_tuples = false;
|
|
nfrozen = 0;
|
|
hastup = false;
|
|
prev_dead_count = dead_tuples->num_tuples;
|
|
maxoff = PageGetMaxOffsetNumber(page);
|
|
|
|
/*
|
|
* Note: If you change anything in the loop below, also look at
|
|
* heap_page_is_all_visible to see if that needs to be changed.
|
|
*/
|
|
for (offnum = FirstOffsetNumber;
|
|
offnum <= maxoff;
|
|
offnum = OffsetNumberNext(offnum))
|
|
{
|
|
ItemId itemid;
|
|
|
|
/*
|
|
* Set the offset number so that we can display it along with any
|
|
* error that occurred while processing this tuple.
|
|
*/
|
|
vacrelstats->offnum = offnum;
|
|
itemid = PageGetItemId(page, offnum);
|
|
|
|
/* Unused items require no processing, but we count 'em */
|
|
if (!ItemIdIsUsed(itemid))
|
|
{
|
|
nunused += 1;
|
|
continue;
|
|
}
|
|
|
|
/* Redirect items mustn't be touched */
|
|
if (ItemIdIsRedirected(itemid))
|
|
{
|
|
hastup = true; /* this page won't be truncatable */
|
|
continue;
|
|
}
|
|
|
|
ItemPointerSet(&(tuple.t_self), blkno, offnum);
|
|
|
|
/*
|
|
* DEAD line pointers are to be vacuumed normally; but we don't
|
|
* count them in tups_vacuumed, else we'd be double-counting (at
|
|
* least in the common case where heap_page_prune() just freed up
|
|
* a non-HOT tuple).
|
|
*/
|
|
if (ItemIdIsDead(itemid))
|
|
{
|
|
lazy_record_dead_tuple(dead_tuples, &(tuple.t_self));
|
|
all_visible = false;
|
|
continue;
|
|
}
|
|
|
|
Assert(ItemIdIsNormal(itemid));
|
|
|
|
tuple.t_data = (HeapTupleHeader) PageGetItem(page, itemid);
|
|
tuple.t_len = ItemIdGetLength(itemid);
|
|
tuple.t_tableOid = RelationGetRelid(onerel);
|
|
|
|
tupgone = false;
|
|
|
|
/*
|
|
* The criteria for counting a tuple as live in this block need to
|
|
* match what analyze.c's acquire_sample_rows() does, otherwise
|
|
* VACUUM and ANALYZE may produce wildly different reltuples
|
|
* values, e.g. when there are many recently-dead tuples.
|
|
*
|
|
* The logic here is a bit simpler than acquire_sample_rows(), as
|
|
* VACUUM can't run inside a transaction block, which makes some
|
|
* cases impossible (e.g. in-progress insert from the same
|
|
* transaction).
|
|
*/
|
|
switch (HeapTupleSatisfiesVacuum(&tuple, OldestXmin, buf))
|
|
{
|
|
case HEAPTUPLE_DEAD:
|
|
|
|
/*
|
|
* Ordinarily, DEAD tuples would have been removed by
|
|
* heap_page_prune(), but it's possible that the tuple
|
|
* state changed since heap_page_prune() looked. In
|
|
* particular an INSERT_IN_PROGRESS tuple could have
|
|
* changed to DEAD if the inserter aborted. So this
|
|
* cannot be considered an error condition.
|
|
*
|
|
* If the tuple is HOT-updated then it must only be
|
|
* removed by a prune operation; so we keep it just as if
|
|
* it were RECENTLY_DEAD. Also, if it's a heap-only
|
|
* tuple, we choose to keep it, because it'll be a lot
|
|
* cheaper to get rid of it in the next pruning pass than
|
|
* to treat it like an indexed tuple. Finally, if index
|
|
* cleanup is disabled, the second heap pass will not
|
|
* execute, and the tuple will not get removed, so we must
|
|
* treat it like any other dead tuple that we choose to
|
|
* keep.
|
|
*
|
|
* If this were to happen for a tuple that actually needed
|
|
* to be deleted, we'd be in trouble, because it'd
|
|
* possibly leave a tuple below the relation's xmin
|
|
* horizon alive. heap_prepare_freeze_tuple() is prepared
|
|
* to detect that case and abort the transaction,
|
|
* preventing corruption.
|
|
*/
|
|
if (HeapTupleIsHotUpdated(&tuple) ||
|
|
HeapTupleIsHeapOnly(&tuple) ||
|
|
params->index_cleanup == VACOPT_TERNARY_DISABLED)
|
|
nkeep += 1;
|
|
else
|
|
tupgone = true; /* we can delete the tuple */
|
|
all_visible = false;
|
|
break;
|
|
case HEAPTUPLE_LIVE:
|
|
|
|
/*
|
|
* Count it as live. Not only is this natural, but it's
|
|
* also what acquire_sample_rows() does.
|
|
*/
|
|
live_tuples += 1;
|
|
|
|
/*
|
|
* Is the tuple definitely visible to all transactions?
|
|
*
|
|
* NB: Like with per-tuple hint bits, we can't set the
|
|
* PD_ALL_VISIBLE flag if the inserter committed
|
|
* asynchronously. See SetHintBits for more info. Check
|
|
* that the tuple is hinted xmin-committed because of
|
|
* that.
|
|
*/
|
|
if (all_visible)
|
|
{
|
|
TransactionId xmin;
|
|
|
|
if (!HeapTupleHeaderXminCommitted(tuple.t_data))
|
|
{
|
|
all_visible = false;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* The inserter definitely committed. But is it old
|
|
* enough that everyone sees it as committed?
|
|
*/
|
|
xmin = HeapTupleHeaderGetXmin(tuple.t_data);
|
|
if (!TransactionIdPrecedes(xmin, OldestXmin))
|
|
{
|
|
all_visible = false;
|
|
break;
|
|
}
|
|
|
|
/* Track newest xmin on page. */
|
|
if (TransactionIdFollows(xmin, visibility_cutoff_xid))
|
|
visibility_cutoff_xid = xmin;
|
|
}
|
|
break;
|
|
case HEAPTUPLE_RECENTLY_DEAD:
|
|
|
|
/*
|
|
* If tuple is recently deleted then we must not remove it
|
|
* from relation.
|
|
*/
|
|
nkeep += 1;
|
|
all_visible = false;
|
|
break;
|
|
case HEAPTUPLE_INSERT_IN_PROGRESS:
|
|
|
|
/*
|
|
* This is an expected case during concurrent vacuum.
|
|
*
|
|
* We do not count these rows as live, because we expect
|
|
* the inserting transaction to update the counters at
|
|
* commit, and we assume that will happen only after we
|
|
* report our results. This assumption is a bit shaky,
|
|
* but it is what acquire_sample_rows() does, so be
|
|
* consistent.
|
|
*/
|
|
all_visible = false;
|
|
break;
|
|
case HEAPTUPLE_DELETE_IN_PROGRESS:
|
|
/* This is an expected case during concurrent vacuum */
|
|
all_visible = false;
|
|
|
|
/*
|
|
* Count such rows as live. As above, we assume the
|
|
* deleting transaction will commit and update the
|
|
* counters after we report.
|
|
*/
|
|
live_tuples += 1;
|
|
break;
|
|
default:
|
|
elog(ERROR, "unexpected HeapTupleSatisfiesVacuum result");
|
|
break;
|
|
}
|
|
|
|
if (tupgone)
|
|
{
|
|
lazy_record_dead_tuple(dead_tuples, &(tuple.t_self));
|
|
HeapTupleHeaderAdvanceLatestRemovedXid(tuple.t_data,
|
|
&vacrelstats->latestRemovedXid);
|
|
tups_vacuumed += 1;
|
|
has_dead_tuples = true;
|
|
}
|
|
else
|
|
{
|
|
bool tuple_totally_frozen;
|
|
|
|
num_tuples += 1;
|
|
hastup = true;
|
|
|
|
/*
|
|
* Each non-removable tuple must be checked to see if it needs
|
|
* freezing. Note we already have exclusive buffer lock.
|
|
*/
|
|
if (heap_prepare_freeze_tuple(tuple.t_data,
|
|
relfrozenxid, relminmxid,
|
|
FreezeLimit, MultiXactCutoff,
|
|
&frozen[nfrozen],
|
|
&tuple_totally_frozen))
|
|
frozen[nfrozen++].offset = offnum;
|
|
|
|
if (!tuple_totally_frozen)
|
|
all_frozen = false;
|
|
}
|
|
} /* scan along page */
|
|
|
|
/*
|
|
* Clear the offset information once we have processed all the tuples
|
|
* on the page.
|
|
*/
|
|
vacrelstats->offnum = InvalidOffsetNumber;
|
|
|
|
/*
|
|
* If we froze any tuples, mark the buffer dirty, and write a WAL
|
|
* record recording the changes. We must log the changes to be
|
|
* crash-safe against future truncation of CLOG.
|
|
*/
|
|
if (nfrozen > 0)
|
|
{
|
|
START_CRIT_SECTION();
|
|
|
|
MarkBufferDirty(buf);
|
|
|
|
/* execute collected freezes */
|
|
for (i = 0; i < nfrozen; i++)
|
|
{
|
|
ItemId itemid;
|
|
HeapTupleHeader htup;
|
|
|
|
itemid = PageGetItemId(page, frozen[i].offset);
|
|
htup = (HeapTupleHeader) PageGetItem(page, itemid);
|
|
|
|
heap_execute_freeze_tuple(htup, &frozen[i]);
|
|
}
|
|
|
|
/* Now WAL-log freezing if necessary */
|
|
if (RelationNeedsWAL(onerel))
|
|
{
|
|
XLogRecPtr recptr;
|
|
|
|
recptr = log_heap_freeze(onerel, buf, FreezeLimit,
|
|
frozen, nfrozen);
|
|
PageSetLSN(page, recptr);
|
|
}
|
|
|
|
END_CRIT_SECTION();
|
|
}
|
|
|
|
/*
|
|
* If there are no indexes we can vacuum the page right now instead of
|
|
* doing a second scan. Also we don't do that but forget dead tuples
|
|
* when index cleanup is disabled.
|
|
*/
|
|
if (!vacrelstats->useindex && dead_tuples->num_tuples > 0)
|
|
{
|
|
if (nindexes == 0)
|
|
{
|
|
/* Remove tuples from heap if the table has no index */
|
|
lazy_vacuum_page(onerel, blkno, buf, 0, vacrelstats, &vmbuffer);
|
|
vacuumed_pages++;
|
|
has_dead_tuples = false;
|
|
}
|
|
else
|
|
{
|
|
/*
|
|
* Here, we have indexes but index cleanup is disabled.
|
|
* Instead of vacuuming the dead tuples on the heap, we just
|
|
* forget them.
|
|
*
|
|
* Note that vacrelstats->dead_tuples could have tuples which
|
|
* became dead after HOT-pruning but are not marked dead yet.
|
|
* We do not process them because it's a very rare condition,
|
|
* and the next vacuum will process them anyway.
|
|
*/
|
|
Assert(params->index_cleanup == VACOPT_TERNARY_DISABLED);
|
|
}
|
|
|
|
/*
|
|
* Forget the now-vacuumed tuples, and press on, but be careful
|
|
* not to reset latestRemovedXid since we want that value to be
|
|
* valid.
|
|
*/
|
|
dead_tuples->num_tuples = 0;
|
|
|
|
/*
|
|
* Periodically do incremental FSM vacuuming to make newly-freed
|
|
* space visible on upper FSM pages. Note: although we've cleaned
|
|
* the current block, we haven't yet updated its FSM entry (that
|
|
* happens further down), so passing end == blkno is correct.
|
|
*/
|
|
if (blkno - next_fsm_block_to_vacuum >= VACUUM_FSM_EVERY_PAGES)
|
|
{
|
|
FreeSpaceMapVacuumRange(onerel, next_fsm_block_to_vacuum,
|
|
blkno);
|
|
next_fsm_block_to_vacuum = blkno;
|
|
}
|
|
}
|
|
|
|
freespace = PageGetHeapFreeSpace(page);
|
|
|
|
/* mark page all-visible, if appropriate */
|
|
if (all_visible && !all_visible_according_to_vm)
|
|
{
|
|
uint8 flags = VISIBILITYMAP_ALL_VISIBLE;
|
|
|
|
if (all_frozen)
|
|
flags |= VISIBILITYMAP_ALL_FROZEN;
|
|
|
|
/*
|
|
* It should never be the case that the visibility map page is set
|
|
* while the page-level bit is clear, but the reverse is allowed
|
|
* (if checksums are not enabled). Regardless, set both bits so
|
|
* that we get back in sync.
|
|
*
|
|
* NB: If the heap page is all-visible but the VM bit is not set,
|
|
* we don't need to dirty the heap page. However, if checksums
|
|
* are enabled, we do need to make sure that the heap page is
|
|
* dirtied before passing it to visibilitymap_set(), because it
|
|
* may be logged. Given that this situation should only happen in
|
|
* rare cases after a crash, it is not worth optimizing.
|
|
*/
|
|
PageSetAllVisible(page);
|
|
MarkBufferDirty(buf);
|
|
visibilitymap_set(onerel, blkno, buf, InvalidXLogRecPtr,
|
|
vmbuffer, visibility_cutoff_xid, flags);
|
|
}
|
|
|
|
/*
|
|
* As of PostgreSQL 9.2, the visibility map bit should never be set if
|
|
* the page-level bit is clear. However, it's possible that the bit
|
|
* got cleared after we checked it and before we took the buffer
|
|
* content lock, so we must recheck before jumping to the conclusion
|
|
* that something bad has happened.
|
|
*/
|
|
else if (all_visible_according_to_vm && !PageIsAllVisible(page)
|
|
&& VM_ALL_VISIBLE(onerel, blkno, &vmbuffer))
|
|
{
|
|
elog(WARNING, "page is not marked all-visible but visibility map bit is set in relation \"%s\" page %u",
|
|
vacrelstats->relname, blkno);
|
|
visibilitymap_clear(onerel, blkno, vmbuffer,
|
|
VISIBILITYMAP_VALID_BITS);
|
|
}
|
|
|
|
/*
|
|
* It's possible for the value returned by
|
|
* GetOldestNonRemovableTransactionId() to move backwards, so it's not
|
|
* wrong for us to see tuples that appear to not be visible to
|
|
* everyone yet, while PD_ALL_VISIBLE is already set. The real safe
|
|
* xmin value never moves backwards, but
|
|
* GetOldestNonRemovableTransactionId() is conservative and sometimes
|
|
* returns a value that's unnecessarily small, so if we see that
|
|
* contradiction it just means that the tuples that we think are not
|
|
* visible to everyone yet actually are, and the PD_ALL_VISIBLE flag
|
|
* is correct.
|
|
*
|
|
* There should never be dead tuples on a page with PD_ALL_VISIBLE
|
|
* set, however.
|
|
*/
|
|
else if (PageIsAllVisible(page) && has_dead_tuples)
|
|
{
|
|
elog(WARNING, "page containing dead tuples is marked as all-visible in relation \"%s\" page %u",
|
|
vacrelstats->relname, blkno);
|
|
PageClearAllVisible(page);
|
|
MarkBufferDirty(buf);
|
|
visibilitymap_clear(onerel, blkno, vmbuffer,
|
|
VISIBILITYMAP_VALID_BITS);
|
|
}
|
|
|
|
/*
|
|
* If the all-visible page is all-frozen but not marked as such yet,
|
|
* mark it as all-frozen. Note that all_frozen is only valid if
|
|
* all_visible is true, so we must check both.
|
|
*/
|
|
else if (all_visible_according_to_vm && all_visible && all_frozen &&
|
|
!VM_ALL_FROZEN(onerel, blkno, &vmbuffer))
|
|
{
|
|
/*
|
|
* We can pass InvalidTransactionId as the cutoff XID here,
|
|
* because setting the all-frozen bit doesn't cause recovery
|
|
* conflicts.
|
|
*/
|
|
visibilitymap_set(onerel, blkno, buf, InvalidXLogRecPtr,
|
|
vmbuffer, InvalidTransactionId,
|
|
VISIBILITYMAP_ALL_FROZEN);
|
|
}
|
|
|
|
UnlockReleaseBuffer(buf);
|
|
|
|
/* Remember the location of the last page with nonremovable tuples */
|
|
if (hastup)
|
|
vacrelstats->nonempty_pages = blkno + 1;
|
|
|
|
/*
|
|
* If we remembered any tuples for deletion, then the page will be
|
|
* visited again by lazy_vacuum_heap, which will compute and record
|
|
* its post-compaction free space. If not, then we're done with this
|
|
* page, so remember its free space as-is. (This path will always be
|
|
* taken if there are no indexes.)
|
|
*/
|
|
if (dead_tuples->num_tuples == prev_dead_count)
|
|
RecordPageWithFreeSpace(onerel, blkno, freespace);
|
|
}
|
|
|
|
/* report that everything is scanned and vacuumed */
|
|
pgstat_progress_update_param(PROGRESS_VACUUM_HEAP_BLKS_SCANNED, blkno);
|
|
|
|
/* Clear the block number information */
|
|
vacrelstats->blkno = InvalidBlockNumber;
|
|
|
|
pfree(frozen);
|
|
|
|
/* save stats for use later */
|
|
vacrelstats->tuples_deleted = tups_vacuumed;
|
|
vacrelstats->new_dead_tuples = nkeep;
|
|
|
|
/* now we can compute the new value for pg_class.reltuples */
|
|
vacrelstats->new_live_tuples = vac_estimate_reltuples(onerel,
|
|
nblocks,
|
|
vacrelstats->tupcount_pages,
|
|
live_tuples);
|
|
|
|
/*
|
|
* Also compute the total number of surviving heap entries. In the
|
|
* (unlikely) scenario that new_live_tuples is -1, take it as zero.
|
|
*/
|
|
vacrelstats->new_rel_tuples =
|
|
Max(vacrelstats->new_live_tuples, 0) + vacrelstats->new_dead_tuples;
|
|
|
|
/*
|
|
* Release any remaining pin on visibility map page.
|
|
*/
|
|
if (BufferIsValid(vmbuffer))
|
|
{
|
|
ReleaseBuffer(vmbuffer);
|
|
vmbuffer = InvalidBuffer;
|
|
}
|
|
|
|
/* If any tuples need to be deleted, perform final vacuum cycle */
|
|
/* XXX put a threshold on min number of tuples here? */
|
|
if (dead_tuples->num_tuples > 0)
|
|
{
|
|
/* Work on all the indexes, and then the heap */
|
|
lazy_vacuum_all_indexes(onerel, Irel, indstats, vacrelstats,
|
|
lps, nindexes);
|
|
|
|
/* Remove tuples from heap */
|
|
lazy_vacuum_heap(onerel, vacrelstats);
|
|
}
|
|
|
|
/*
|
|
* Vacuum the remainder of the Free Space Map. We must do this whether or
|
|
* not there were indexes.
|
|
*/
|
|
if (blkno > next_fsm_block_to_vacuum)
|
|
FreeSpaceMapVacuumRange(onerel, next_fsm_block_to_vacuum, blkno);
|
|
|
|
/* report all blocks vacuumed */
|
|
pgstat_progress_update_param(PROGRESS_VACUUM_HEAP_BLKS_VACUUMED, blkno);
|
|
|
|
/* Do post-vacuum cleanup */
|
|
if (vacrelstats->useindex)
|
|
lazy_cleanup_all_indexes(Irel, indstats, vacrelstats, lps, nindexes);
|
|
|
|
/*
|
|
* End parallel mode before updating index statistics as we cannot write
|
|
* during parallel mode.
|
|
*/
|
|
if (ParallelVacuumIsActive(lps))
|
|
end_parallel_vacuum(indstats, lps, nindexes);
|
|
|
|
/* Update index statistics */
|
|
update_index_statistics(Irel, indstats, nindexes);
|
|
|
|
/* If no indexes, make log report that lazy_vacuum_heap would've made */
|
|
if (vacuumed_pages)
|
|
ereport(elevel,
|
|
(errmsg("\"%s\": removed %.0f row versions in %u pages",
|
|
vacrelstats->relname,
|
|
tups_vacuumed, vacuumed_pages)));
|
|
|
|
/*
|
|
* This is pretty messy, but we split it up so that we can skip emitting
|
|
* individual parts of the message when not applicable.
|
|
*/
|
|
initStringInfo(&buf);
|
|
appendStringInfo(&buf,
|
|
_("%.0f dead row versions cannot be removed yet, oldest xmin: %u\n"),
|
|
nkeep, OldestXmin);
|
|
appendStringInfo(&buf, _("There were %.0f unused item identifiers.\n"),
|
|
nunused);
|
|
appendStringInfo(&buf, ngettext("Skipped %u page due to buffer pins, ",
|
|
"Skipped %u pages due to buffer pins, ",
|
|
vacrelstats->pinskipped_pages),
|
|
vacrelstats->pinskipped_pages);
|
|
appendStringInfo(&buf, ngettext("%u frozen page.\n",
|
|
"%u frozen pages.\n",
|
|
vacrelstats->frozenskipped_pages),
|
|
vacrelstats->frozenskipped_pages);
|
|
appendStringInfo(&buf, ngettext("%u page is entirely empty.\n",
|
|
"%u pages are entirely empty.\n",
|
|
empty_pages),
|
|
empty_pages);
|
|
appendStringInfo(&buf, _("%s."), pg_rusage_show(&ru0));
|
|
|
|
ereport(elevel,
|
|
(errmsg("\"%s\": found %.0f removable, %.0f nonremovable row versions in %u out of %u pages",
|
|
vacrelstats->relname,
|
|
tups_vacuumed, num_tuples,
|
|
vacrelstats->scanned_pages, nblocks),
|
|
errdetail_internal("%s", buf.data)));
|
|
pfree(buf.data);
|
|
}
|
|
|
|
/*
|
|
* lazy_vacuum_all_indexes() -- vacuum all indexes of relation.
|
|
*
|
|
* We process the indexes serially unless we are doing parallel vacuum.
|
|
*/
|
|
static void
|
|
lazy_vacuum_all_indexes(Relation onerel, Relation *Irel,
|
|
IndexBulkDeleteResult **stats,
|
|
LVRelStats *vacrelstats, LVParallelState *lps,
|
|
int nindexes)
|
|
{
|
|
Assert(!IsParallelWorker());
|
|
Assert(nindexes > 0);
|
|
|
|
/* Log cleanup info before we touch indexes */
|
|
vacuum_log_cleanup_info(onerel, vacrelstats);
|
|
|
|
/* Report that we are now vacuuming indexes */
|
|
pgstat_progress_update_param(PROGRESS_VACUUM_PHASE,
|
|
PROGRESS_VACUUM_PHASE_VACUUM_INDEX);
|
|
|
|
/* Perform index vacuuming with parallel workers for parallel vacuum. */
|
|
if (ParallelVacuumIsActive(lps))
|
|
{
|
|
/* Tell parallel workers to do index vacuuming */
|
|
lps->lvshared->for_cleanup = false;
|
|
lps->lvshared->first_time = false;
|
|
|
|
/*
|
|
* We can only provide an approximate value of num_heap_tuples in
|
|
* vacuum cases.
|
|
*/
|
|
lps->lvshared->reltuples = vacrelstats->old_live_tuples;
|
|
lps->lvshared->estimated_count = true;
|
|
|
|
lazy_parallel_vacuum_indexes(Irel, stats, vacrelstats, lps, nindexes);
|
|
}
|
|
else
|
|
{
|
|
int idx;
|
|
|
|
for (idx = 0; idx < nindexes; idx++)
|
|
lazy_vacuum_index(Irel[idx], &stats[idx], vacrelstats->dead_tuples,
|
|
vacrelstats->old_live_tuples, vacrelstats);
|
|
}
|
|
|
|
/* Increase and report the number of index scans */
|
|
vacrelstats->num_index_scans++;
|
|
pgstat_progress_update_param(PROGRESS_VACUUM_NUM_INDEX_VACUUMS,
|
|
vacrelstats->num_index_scans);
|
|
}
|
|
|
|
|
|
/*
|
|
* lazy_vacuum_heap() -- second pass over the heap
|
|
*
|
|
* This routine marks dead tuples as unused and compacts out free
|
|
* space on their pages. Pages not having dead tuples recorded from
|
|
* lazy_scan_heap are not visited at all.
|
|
*
|
|
* Note: the reason for doing this as a second pass is we cannot remove
|
|
* the tuples until we've removed their index entries, and we want to
|
|
* process index entry removal in batches as large as possible.
|
|
*/
|
|
static void
|
|
lazy_vacuum_heap(Relation onerel, LVRelStats *vacrelstats)
|
|
{
|
|
int tupindex;
|
|
int npages;
|
|
PGRUsage ru0;
|
|
Buffer vmbuffer = InvalidBuffer;
|
|
LVSavedErrInfo saved_err_info;
|
|
|
|
/* Report that we are now vacuuming the heap */
|
|
pgstat_progress_update_param(PROGRESS_VACUUM_PHASE,
|
|
PROGRESS_VACUUM_PHASE_VACUUM_HEAP);
|
|
|
|
/* Update error traceback information */
|
|
update_vacuum_error_info(vacrelstats, &saved_err_info, VACUUM_ERRCB_PHASE_VACUUM_HEAP,
|
|
InvalidBlockNumber, InvalidOffsetNumber);
|
|
|
|
pg_rusage_init(&ru0);
|
|
npages = 0;
|
|
|
|
tupindex = 0;
|
|
while (tupindex < vacrelstats->dead_tuples->num_tuples)
|
|
{
|
|
BlockNumber tblk;
|
|
Buffer buf;
|
|
Page page;
|
|
Size freespace;
|
|
|
|
vacuum_delay_point();
|
|
|
|
tblk = ItemPointerGetBlockNumber(&vacrelstats->dead_tuples->itemptrs[tupindex]);
|
|
vacrelstats->blkno = tblk;
|
|
buf = ReadBufferExtended(onerel, MAIN_FORKNUM, tblk, RBM_NORMAL,
|
|
vac_strategy);
|
|
if (!ConditionalLockBufferForCleanup(buf))
|
|
{
|
|
ReleaseBuffer(buf);
|
|
++tupindex;
|
|
continue;
|
|
}
|
|
tupindex = lazy_vacuum_page(onerel, tblk, buf, tupindex, vacrelstats,
|
|
&vmbuffer);
|
|
|
|
/* Now that we've compacted the page, record its available space */
|
|
page = BufferGetPage(buf);
|
|
freespace = PageGetHeapFreeSpace(page);
|
|
|
|
UnlockReleaseBuffer(buf);
|
|
RecordPageWithFreeSpace(onerel, tblk, freespace);
|
|
npages++;
|
|
}
|
|
|
|
/* Clear the block number information */
|
|
vacrelstats->blkno = InvalidBlockNumber;
|
|
|
|
if (BufferIsValid(vmbuffer))
|
|
{
|
|
ReleaseBuffer(vmbuffer);
|
|
vmbuffer = InvalidBuffer;
|
|
}
|
|
|
|
ereport(elevel,
|
|
(errmsg("\"%s\": removed %d row versions in %d pages",
|
|
vacrelstats->relname,
|
|
tupindex, npages),
|
|
errdetail_internal("%s", pg_rusage_show(&ru0))));
|
|
|
|
/* Revert to the previous phase information for error traceback */
|
|
restore_vacuum_error_info(vacrelstats, &saved_err_info);
|
|
}
|
|
|
|
/*
|
|
* lazy_vacuum_page() -- free dead tuples on a page
|
|
* and repair its fragmentation.
|
|
*
|
|
* Caller must hold pin and buffer cleanup lock on the buffer.
|
|
*
|
|
* tupindex is the index in vacrelstats->dead_tuples of the first dead
|
|
* tuple for this page. We assume the rest follow sequentially.
|
|
* The return value is the first tupindex after the tuples of this page.
|
|
*/
|
|
static int
|
|
lazy_vacuum_page(Relation onerel, BlockNumber blkno, Buffer buffer,
|
|
int tupindex, LVRelStats *vacrelstats, Buffer *vmbuffer)
|
|
{
|
|
LVDeadTuples *dead_tuples = vacrelstats->dead_tuples;
|
|
Page page = BufferGetPage(buffer);
|
|
OffsetNumber unused[MaxOffsetNumber];
|
|
int uncnt = 0;
|
|
TransactionId visibility_cutoff_xid;
|
|
bool all_frozen;
|
|
LVSavedErrInfo saved_err_info;
|
|
|
|
pgstat_progress_update_param(PROGRESS_VACUUM_HEAP_BLKS_VACUUMED, blkno);
|
|
|
|
/* Update error traceback information */
|
|
update_vacuum_error_info(vacrelstats, &saved_err_info, VACUUM_ERRCB_PHASE_VACUUM_HEAP,
|
|
blkno, InvalidOffsetNumber);
|
|
|
|
START_CRIT_SECTION();
|
|
|
|
for (; tupindex < dead_tuples->num_tuples; tupindex++)
|
|
{
|
|
BlockNumber tblk;
|
|
OffsetNumber toff;
|
|
ItemId itemid;
|
|
|
|
tblk = ItemPointerGetBlockNumber(&dead_tuples->itemptrs[tupindex]);
|
|
if (tblk != blkno)
|
|
break; /* past end of tuples for this block */
|
|
toff = ItemPointerGetOffsetNumber(&dead_tuples->itemptrs[tupindex]);
|
|
itemid = PageGetItemId(page, toff);
|
|
ItemIdSetUnused(itemid);
|
|
unused[uncnt++] = toff;
|
|
}
|
|
|
|
PageRepairFragmentation(page);
|
|
|
|
/*
|
|
* Mark buffer dirty before we write WAL.
|
|
*/
|
|
MarkBufferDirty(buffer);
|
|
|
|
/* XLOG stuff */
|
|
if (RelationNeedsWAL(onerel))
|
|
{
|
|
XLogRecPtr recptr;
|
|
|
|
recptr = log_heap_clean(onerel, buffer,
|
|
NULL, 0, NULL, 0,
|
|
unused, uncnt,
|
|
vacrelstats->latestRemovedXid);
|
|
PageSetLSN(page, recptr);
|
|
}
|
|
|
|
/*
|
|
* End critical section, so we safely can do visibility tests (which
|
|
* possibly need to perform IO and allocate memory!). If we crash now the
|
|
* page (including the corresponding vm bit) might not be marked all
|
|
* visible, but that's fine. A later vacuum will fix that.
|
|
*/
|
|
END_CRIT_SECTION();
|
|
|
|
/*
|
|
* Now that we have removed the dead tuples from the page, once again
|
|
* check if the page has become all-visible. The page is already marked
|
|
* dirty, exclusively locked, and, if needed, a full page image has been
|
|
* emitted in the log_heap_clean() above.
|
|
*/
|
|
if (heap_page_is_all_visible(onerel, buffer, vacrelstats,
|
|
&visibility_cutoff_xid,
|
|
&all_frozen))
|
|
PageSetAllVisible(page);
|
|
|
|
/*
|
|
* All the changes to the heap page have been done. If the all-visible
|
|
* flag is now set, also set the VM all-visible bit (and, if possible, the
|
|
* all-frozen bit) unless this has already been done previously.
|
|
*/
|
|
if (PageIsAllVisible(page))
|
|
{
|
|
uint8 vm_status = visibilitymap_get_status(onerel, blkno, vmbuffer);
|
|
uint8 flags = 0;
|
|
|
|
/* Set the VM all-frozen bit to flag, if needed */
|
|
if ((vm_status & VISIBILITYMAP_ALL_VISIBLE) == 0)
|
|
flags |= VISIBILITYMAP_ALL_VISIBLE;
|
|
if ((vm_status & VISIBILITYMAP_ALL_FROZEN) == 0 && all_frozen)
|
|
flags |= VISIBILITYMAP_ALL_FROZEN;
|
|
|
|
Assert(BufferIsValid(*vmbuffer));
|
|
if (flags != 0)
|
|
visibilitymap_set(onerel, blkno, buffer, InvalidXLogRecPtr,
|
|
*vmbuffer, visibility_cutoff_xid, flags);
|
|
}
|
|
|
|
/* Revert to the previous phase information for error traceback */
|
|
restore_vacuum_error_info(vacrelstats, &saved_err_info);
|
|
return tupindex;
|
|
}
|
|
|
|
/*
|
|
* lazy_check_needs_freeze() -- scan page to see if any tuples
|
|
* need to be cleaned to avoid wraparound
|
|
*
|
|
* Returns true if the page needs to be vacuumed using cleanup lock.
|
|
* Also returns a flag indicating whether page contains any tuples at all.
|
|
*/
|
|
static bool
|
|
lazy_check_needs_freeze(Buffer buf, bool *hastup, LVRelStats *vacrelstats)
|
|
{
|
|
Page page = BufferGetPage(buf);
|
|
OffsetNumber offnum,
|
|
maxoff;
|
|
HeapTupleHeader tupleheader;
|
|
|
|
*hastup = false;
|
|
|
|
/*
|
|
* New and empty pages, obviously, don't contain tuples. We could make
|
|
* sure that the page is registered in the FSM, but it doesn't seem worth
|
|
* waiting for a cleanup lock just for that, especially because it's
|
|
* likely that the pin holder will do so.
|
|
*/
|
|
if (PageIsNew(page) || PageIsEmpty(page))
|
|
return false;
|
|
|
|
maxoff = PageGetMaxOffsetNumber(page);
|
|
for (offnum = FirstOffsetNumber;
|
|
offnum <= maxoff;
|
|
offnum = OffsetNumberNext(offnum))
|
|
{
|
|
ItemId itemid;
|
|
|
|
/*
|
|
* Set the offset number so that we can display it along with any
|
|
* error that occurred while processing this tuple.
|
|
*/
|
|
vacrelstats->offnum = offnum;
|
|
itemid = PageGetItemId(page, offnum);
|
|
|
|
/* this should match hastup test in count_nondeletable_pages() */
|
|
if (ItemIdIsUsed(itemid))
|
|
*hastup = true;
|
|
|
|
/* dead and redirect items never need freezing */
|
|
if (!ItemIdIsNormal(itemid))
|
|
continue;
|
|
|
|
tupleheader = (HeapTupleHeader) PageGetItem(page, itemid);
|
|
|
|
if (heap_tuple_needs_freeze(tupleheader, FreezeLimit,
|
|
MultiXactCutoff, buf))
|
|
break;
|
|
} /* scan along page */
|
|
|
|
/* Clear the offset information once we have processed the given page. */
|
|
vacrelstats->offnum = InvalidOffsetNumber;
|
|
|
|
return (offnum <= maxoff);
|
|
}
|
|
|
|
/*
|
|
* Perform index vacuum or index cleanup with parallel workers. This function
|
|
* must be used by the parallel vacuum leader process. The caller must set
|
|
* lps->lvshared->for_cleanup to indicate whether to perform vacuum or
|
|
* cleanup.
|
|
*/
|
|
static void
|
|
lazy_parallel_vacuum_indexes(Relation *Irel, IndexBulkDeleteResult **stats,
|
|
LVRelStats *vacrelstats, LVParallelState *lps,
|
|
int nindexes)
|
|
{
|
|
int nworkers;
|
|
|
|
Assert(!IsParallelWorker());
|
|
Assert(ParallelVacuumIsActive(lps));
|
|
Assert(nindexes > 0);
|
|
|
|
/* Determine the number of parallel workers to launch */
|
|
if (lps->lvshared->for_cleanup)
|
|
{
|
|
if (lps->lvshared->first_time)
|
|
nworkers = lps->nindexes_parallel_cleanup +
|
|
lps->nindexes_parallel_condcleanup;
|
|
else
|
|
nworkers = lps->nindexes_parallel_cleanup;
|
|
}
|
|
else
|
|
nworkers = lps->nindexes_parallel_bulkdel;
|
|
|
|
/* The leader process will participate */
|
|
nworkers--;
|
|
|
|
/*
|
|
* It is possible that parallel context is initialized with fewer workers
|
|
* than the number of indexes that need a separate worker in the current
|
|
* phase, so we need to consider it. See compute_parallel_vacuum_workers.
|
|
*/
|
|
nworkers = Min(nworkers, lps->pcxt->nworkers);
|
|
|
|
/* Setup the shared cost-based vacuum delay and launch workers */
|
|
if (nworkers > 0)
|
|
{
|
|
if (vacrelstats->num_index_scans > 0)
|
|
{
|
|
/* Reset the parallel index processing counter */
|
|
pg_atomic_write_u32(&(lps->lvshared->idx), 0);
|
|
|
|
/* Reinitialize the parallel context to relaunch parallel workers */
|
|
ReinitializeParallelDSM(lps->pcxt);
|
|
}
|
|
|
|
/*
|
|
* Set up shared cost balance and the number of active workers for
|
|
* vacuum delay. We need to do this before launching workers as
|
|
* otherwise, they might not see the updated values for these
|
|
* parameters.
|
|
*/
|
|
pg_atomic_write_u32(&(lps->lvshared->cost_balance), VacuumCostBalance);
|
|
pg_atomic_write_u32(&(lps->lvshared->active_nworkers), 0);
|
|
|
|
/*
|
|
* The number of workers can vary between bulkdelete and cleanup
|
|
* phase.
|
|
*/
|
|
ReinitializeParallelWorkers(lps->pcxt, nworkers);
|
|
|
|
LaunchParallelWorkers(lps->pcxt);
|
|
|
|
if (lps->pcxt->nworkers_launched > 0)
|
|
{
|
|
/*
|
|
* Reset the local cost values for leader backend as we have
|
|
* already accumulated the remaining balance of heap.
|
|
*/
|
|
VacuumCostBalance = 0;
|
|
VacuumCostBalanceLocal = 0;
|
|
|
|
/* Enable shared cost balance for leader backend */
|
|
VacuumSharedCostBalance = &(lps->lvshared->cost_balance);
|
|
VacuumActiveNWorkers = &(lps->lvshared->active_nworkers);
|
|
}
|
|
|
|
if (lps->lvshared->for_cleanup)
|
|
ereport(elevel,
|
|
(errmsg(ngettext("launched %d parallel vacuum worker for index cleanup (planned: %d)",
|
|
"launched %d parallel vacuum workers for index cleanup (planned: %d)",
|
|
lps->pcxt->nworkers_launched),
|
|
lps->pcxt->nworkers_launched, nworkers)));
|
|
else
|
|
ereport(elevel,
|
|
(errmsg(ngettext("launched %d parallel vacuum worker for index vacuuming (planned: %d)",
|
|
"launched %d parallel vacuum workers for index vacuuming (planned: %d)",
|
|
lps->pcxt->nworkers_launched),
|
|
lps->pcxt->nworkers_launched, nworkers)));
|
|
}
|
|
|
|
/* Process the indexes that can be processed by only leader process */
|
|
vacuum_indexes_leader(Irel, stats, vacrelstats, lps, nindexes);
|
|
|
|
/*
|
|
* Join as a parallel worker. The leader process alone processes all the
|
|
* indexes in the case where no workers are launched.
|
|
*/
|
|
parallel_vacuum_index(Irel, stats, lps->lvshared,
|
|
vacrelstats->dead_tuples, nindexes, vacrelstats);
|
|
|
|
/*
|
|
* Next, accumulate buffer and WAL usage. (This must wait for the workers
|
|
* to finish, or we might get incomplete data.)
|
|
*/
|
|
if (nworkers > 0)
|
|
{
|
|
int i;
|
|
|
|
/* Wait for all vacuum workers to finish */
|
|
WaitForParallelWorkersToFinish(lps->pcxt);
|
|
|
|
for (i = 0; i < lps->pcxt->nworkers_launched; i++)
|
|
InstrAccumParallelQuery(&lps->buffer_usage[i], &lps->wal_usage[i]);
|
|
}
|
|
|
|
/*
|
|
* Carry the shared balance value to heap scan and disable shared costing
|
|
*/
|
|
if (VacuumSharedCostBalance)
|
|
{
|
|
VacuumCostBalance = pg_atomic_read_u32(VacuumSharedCostBalance);
|
|
VacuumSharedCostBalance = NULL;
|
|
VacuumActiveNWorkers = NULL;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Index vacuum/cleanup routine used by the leader process and parallel
|
|
* vacuum worker processes to process the indexes in parallel.
|
|
*/
|
|
static void
|
|
parallel_vacuum_index(Relation *Irel, IndexBulkDeleteResult **stats,
|
|
LVShared *lvshared, LVDeadTuples *dead_tuples,
|
|
int nindexes, LVRelStats *vacrelstats)
|
|
{
|
|
/*
|
|
* Increment the active worker count if we are able to launch any worker.
|
|
*/
|
|
if (VacuumActiveNWorkers)
|
|
pg_atomic_add_fetch_u32(VacuumActiveNWorkers, 1);
|
|
|
|
/* Loop until all indexes are vacuumed */
|
|
for (;;)
|
|
{
|
|
int idx;
|
|
LVSharedIndStats *shared_indstats;
|
|
|
|
/* Get an index number to process */
|
|
idx = pg_atomic_fetch_add_u32(&(lvshared->idx), 1);
|
|
|
|
/* Done for all indexes? */
|
|
if (idx >= nindexes)
|
|
break;
|
|
|
|
/* Get the index statistics of this index from DSM */
|
|
shared_indstats = get_indstats(lvshared, idx);
|
|
|
|
/*
|
|
* Skip processing indexes that don't participate in parallel
|
|
* operation
|
|
*/
|
|
if (shared_indstats == NULL ||
|
|
skip_parallel_vacuum_index(Irel[idx], lvshared))
|
|
continue;
|
|
|
|
/* Do vacuum or cleanup of the index */
|
|
vacuum_one_index(Irel[idx], &(stats[idx]), lvshared, shared_indstats,
|
|
dead_tuples, vacrelstats);
|
|
}
|
|
|
|
/*
|
|
* We have completed the index vacuum so decrement the active worker
|
|
* count.
|
|
*/
|
|
if (VacuumActiveNWorkers)
|
|
pg_atomic_sub_fetch_u32(VacuumActiveNWorkers, 1);
|
|
}
|
|
|
|
/*
|
|
* Vacuum or cleanup indexes that can be processed by only the leader process
|
|
* because these indexes don't support parallel operation at that phase.
|
|
*/
|
|
static void
|
|
vacuum_indexes_leader(Relation *Irel, IndexBulkDeleteResult **stats,
|
|
LVRelStats *vacrelstats, LVParallelState *lps,
|
|
int nindexes)
|
|
{
|
|
int i;
|
|
|
|
Assert(!IsParallelWorker());
|
|
|
|
/*
|
|
* Increment the active worker count if we are able to launch any worker.
|
|
*/
|
|
if (VacuumActiveNWorkers)
|
|
pg_atomic_add_fetch_u32(VacuumActiveNWorkers, 1);
|
|
|
|
for (i = 0; i < nindexes; i++)
|
|
{
|
|
LVSharedIndStats *shared_indstats;
|
|
|
|
shared_indstats = get_indstats(lps->lvshared, i);
|
|
|
|
/* Process the indexes skipped by parallel workers */
|
|
if (shared_indstats == NULL ||
|
|
skip_parallel_vacuum_index(Irel[i], lps->lvshared))
|
|
vacuum_one_index(Irel[i], &(stats[i]), lps->lvshared,
|
|
shared_indstats, vacrelstats->dead_tuples,
|
|
vacrelstats);
|
|
}
|
|
|
|
/*
|
|
* We have completed the index vacuum so decrement the active worker
|
|
* count.
|
|
*/
|
|
if (VacuumActiveNWorkers)
|
|
pg_atomic_sub_fetch_u32(VacuumActiveNWorkers, 1);
|
|
}
|
|
|
|
/*
|
|
* Vacuum or cleanup index either by leader process or by one of the worker
|
|
* process. After processing the index this function copies the index
|
|
* statistics returned from ambulkdelete and amvacuumcleanup to the DSM
|
|
* segment.
|
|
*/
|
|
static void
|
|
vacuum_one_index(Relation indrel, IndexBulkDeleteResult **stats,
|
|
LVShared *lvshared, LVSharedIndStats *shared_indstats,
|
|
LVDeadTuples *dead_tuples, LVRelStats *vacrelstats)
|
|
{
|
|
IndexBulkDeleteResult *bulkdelete_res = NULL;
|
|
|
|
if (shared_indstats)
|
|
{
|
|
/* Get the space for IndexBulkDeleteResult */
|
|
bulkdelete_res = &(shared_indstats->stats);
|
|
|
|
/*
|
|
* Update the pointer to the corresponding bulk-deletion result if
|
|
* someone has already updated it.
|
|
*/
|
|
if (shared_indstats->updated && *stats == NULL)
|
|
*stats = bulkdelete_res;
|
|
}
|
|
|
|
/* Do vacuum or cleanup of the index */
|
|
if (lvshared->for_cleanup)
|
|
lazy_cleanup_index(indrel, stats, lvshared->reltuples,
|
|
lvshared->estimated_count, vacrelstats);
|
|
else
|
|
lazy_vacuum_index(indrel, stats, dead_tuples,
|
|
lvshared->reltuples, vacrelstats);
|
|
|
|
/*
|
|
* Copy the index bulk-deletion result returned from ambulkdelete and
|
|
* amvacuumcleanup to the DSM segment if it's the first cycle because they
|
|
* allocate locally and it's possible that an index will be vacuumed by a
|
|
* different vacuum process the next cycle. Copying the result normally
|
|
* happens only the first time an index is vacuumed. For any additional
|
|
* vacuum pass, we directly point to the result on the DSM segment and
|
|
* pass it to vacuum index APIs so that workers can update it directly.
|
|
*
|
|
* Since all vacuum workers write the bulk-deletion result at different
|
|
* slots we can write them without locking.
|
|
*/
|
|
if (shared_indstats && !shared_indstats->updated && *stats != NULL)
|
|
{
|
|
memcpy(bulkdelete_res, *stats, sizeof(IndexBulkDeleteResult));
|
|
shared_indstats->updated = true;
|
|
|
|
/*
|
|
* Now that stats[idx] points to the DSM segment, we don't need the
|
|
* locally allocated results.
|
|
*/
|
|
pfree(*stats);
|
|
*stats = bulkdelete_res;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* lazy_cleanup_all_indexes() -- cleanup all indexes of relation.
|
|
*
|
|
* Cleanup indexes. We process the indexes serially unless we are doing
|
|
* parallel vacuum.
|
|
*/
|
|
static void
|
|
lazy_cleanup_all_indexes(Relation *Irel, IndexBulkDeleteResult **stats,
|
|
LVRelStats *vacrelstats, LVParallelState *lps,
|
|
int nindexes)
|
|
{
|
|
int idx;
|
|
|
|
Assert(!IsParallelWorker());
|
|
Assert(nindexes > 0);
|
|
|
|
/* Report that we are now cleaning up indexes */
|
|
pgstat_progress_update_param(PROGRESS_VACUUM_PHASE,
|
|
PROGRESS_VACUUM_PHASE_INDEX_CLEANUP);
|
|
|
|
/*
|
|
* If parallel vacuum is active we perform index cleanup with parallel
|
|
* workers.
|
|
*/
|
|
if (ParallelVacuumIsActive(lps))
|
|
{
|
|
/* Tell parallel workers to do index cleanup */
|
|
lps->lvshared->for_cleanup = true;
|
|
lps->lvshared->first_time =
|
|
(vacrelstats->num_index_scans == 0);
|
|
|
|
/*
|
|
* Now we can provide a better estimate of total number of surviving
|
|
* tuples (we assume indexes are more interested in that than in the
|
|
* number of nominally live tuples).
|
|
*/
|
|
lps->lvshared->reltuples = vacrelstats->new_rel_tuples;
|
|
lps->lvshared->estimated_count =
|
|
(vacrelstats->tupcount_pages < vacrelstats->rel_pages);
|
|
|
|
lazy_parallel_vacuum_indexes(Irel, stats, vacrelstats, lps, nindexes);
|
|
}
|
|
else
|
|
{
|
|
for (idx = 0; idx < nindexes; idx++)
|
|
lazy_cleanup_index(Irel[idx], &stats[idx],
|
|
vacrelstats->new_rel_tuples,
|
|
vacrelstats->tupcount_pages < vacrelstats->rel_pages,
|
|
vacrelstats);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* lazy_vacuum_index() -- vacuum one index relation.
|
|
*
|
|
* Delete all the index entries pointing to tuples listed in
|
|
* dead_tuples, and update running statistics.
|
|
*
|
|
* reltuples is the number of heap tuples to be passed to the
|
|
* bulkdelete callback. It's always assumed to be estimated.
|
|
*/
|
|
static void
|
|
lazy_vacuum_index(Relation indrel, IndexBulkDeleteResult **stats,
|
|
LVDeadTuples *dead_tuples, double reltuples, LVRelStats *vacrelstats)
|
|
{
|
|
IndexVacuumInfo ivinfo;
|
|
const char *msg;
|
|
PGRUsage ru0;
|
|
LVSavedErrInfo saved_err_info;
|
|
|
|
pg_rusage_init(&ru0);
|
|
|
|
ivinfo.index = indrel;
|
|
ivinfo.analyze_only = false;
|
|
ivinfo.report_progress = false;
|
|
ivinfo.estimated_count = true;
|
|
ivinfo.message_level = elevel;
|
|
ivinfo.num_heap_tuples = reltuples;
|
|
ivinfo.strategy = vac_strategy;
|
|
|
|
/*
|
|
* Update error traceback information.
|
|
*
|
|
* The index name is saved during this phase and restored immediately
|
|
* after this phase. See vacuum_error_callback.
|
|
*/
|
|
Assert(vacrelstats->indname == NULL);
|
|
vacrelstats->indname = pstrdup(RelationGetRelationName(indrel));
|
|
update_vacuum_error_info(vacrelstats, &saved_err_info,
|
|
VACUUM_ERRCB_PHASE_VACUUM_INDEX,
|
|
InvalidBlockNumber, InvalidOffsetNumber);
|
|
|
|
/* Do bulk deletion */
|
|
*stats = index_bulk_delete(&ivinfo, *stats,
|
|
lazy_tid_reaped, (void *) dead_tuples);
|
|
|
|
if (IsParallelWorker())
|
|
msg = gettext_noop("scanned index \"%s\" to remove %d row versions by parallel vacuum worker");
|
|
else
|
|
msg = gettext_noop("scanned index \"%s\" to remove %d row versions");
|
|
|
|
ereport(elevel,
|
|
(errmsg(msg,
|
|
vacrelstats->indname,
|
|
dead_tuples->num_tuples),
|
|
errdetail_internal("%s", pg_rusage_show(&ru0))));
|
|
|
|
/* Revert to the previous phase information for error traceback */
|
|
restore_vacuum_error_info(vacrelstats, &saved_err_info);
|
|
pfree(vacrelstats->indname);
|
|
vacrelstats->indname = NULL;
|
|
}
|
|
|
|
/*
|
|
* lazy_cleanup_index() -- do post-vacuum cleanup for one index relation.
|
|
*
|
|
* reltuples is the number of heap tuples and estimated_count is true
|
|
* if reltuples is an estimated value.
|
|
*/
|
|
static void
|
|
lazy_cleanup_index(Relation indrel,
|
|
IndexBulkDeleteResult **stats,
|
|
double reltuples, bool estimated_count, LVRelStats *vacrelstats)
|
|
{
|
|
IndexVacuumInfo ivinfo;
|
|
const char *msg;
|
|
PGRUsage ru0;
|
|
LVSavedErrInfo saved_err_info;
|
|
|
|
pg_rusage_init(&ru0);
|
|
|
|
ivinfo.index = indrel;
|
|
ivinfo.analyze_only = false;
|
|
ivinfo.report_progress = false;
|
|
ivinfo.estimated_count = estimated_count;
|
|
ivinfo.message_level = elevel;
|
|
|
|
ivinfo.num_heap_tuples = reltuples;
|
|
ivinfo.strategy = vac_strategy;
|
|
|
|
/*
|
|
* Update error traceback information.
|
|
*
|
|
* The index name is saved during this phase and restored immediately
|
|
* after this phase. See vacuum_error_callback.
|
|
*/
|
|
Assert(vacrelstats->indname == NULL);
|
|
vacrelstats->indname = pstrdup(RelationGetRelationName(indrel));
|
|
update_vacuum_error_info(vacrelstats, &saved_err_info,
|
|
VACUUM_ERRCB_PHASE_INDEX_CLEANUP,
|
|
InvalidBlockNumber, InvalidOffsetNumber);
|
|
|
|
*stats = index_vacuum_cleanup(&ivinfo, *stats);
|
|
|
|
if (*stats)
|
|
{
|
|
if (IsParallelWorker())
|
|
msg = gettext_noop("index \"%s\" now contains %.0f row versions in %u pages as reported by parallel vacuum worker");
|
|
else
|
|
msg = gettext_noop("index \"%s\" now contains %.0f row versions in %u pages");
|
|
|
|
ereport(elevel,
|
|
(errmsg(msg,
|
|
RelationGetRelationName(indrel),
|
|
(*stats)->num_index_tuples,
|
|
(*stats)->num_pages),
|
|
errdetail("%.0f index row versions were removed.\n"
|
|
"%u index pages have been deleted, %u are currently reusable.\n"
|
|
"%s.",
|
|
(*stats)->tuples_removed,
|
|
(*stats)->pages_deleted, (*stats)->pages_free,
|
|
pg_rusage_show(&ru0))));
|
|
}
|
|
|
|
/* Revert to the previous phase information for error traceback */
|
|
restore_vacuum_error_info(vacrelstats, &saved_err_info);
|
|
pfree(vacrelstats->indname);
|
|
vacrelstats->indname = NULL;
|
|
}
|
|
|
|
/*
|
|
* should_attempt_truncation - should we attempt to truncate the heap?
|
|
*
|
|
* Don't even think about it unless we have a shot at releasing a goodly
|
|
* number of pages. Otherwise, the time taken isn't worth it.
|
|
*
|
|
* Also don't attempt it if we are doing early pruning/vacuuming, because a
|
|
* scan which cannot find a truncated heap page cannot determine that the
|
|
* snapshot is too old to read that page. We might be able to get away with
|
|
* truncating all except one of the pages, setting its LSN to (at least) the
|
|
* maximum of the truncated range if we also treated an index leaf tuple
|
|
* pointing to a missing heap page as something to trigger the "snapshot too
|
|
* old" error, but that seems fragile and seems like it deserves its own patch
|
|
* if we consider it.
|
|
*
|
|
* This is split out so that we can test whether truncation is going to be
|
|
* called for before we actually do it. If you change the logic here, be
|
|
* careful to depend only on fields that lazy_scan_heap updates on-the-fly.
|
|
*/
|
|
static bool
|
|
should_attempt_truncation(VacuumParams *params, LVRelStats *vacrelstats)
|
|
{
|
|
BlockNumber possibly_freeable;
|
|
|
|
if (params->truncate == VACOPT_TERNARY_DISABLED)
|
|
return false;
|
|
|
|
possibly_freeable = vacrelstats->rel_pages - vacrelstats->nonempty_pages;
|
|
if (possibly_freeable > 0 &&
|
|
(possibly_freeable >= REL_TRUNCATE_MINIMUM ||
|
|
possibly_freeable >= vacrelstats->rel_pages / REL_TRUNCATE_FRACTION) &&
|
|
old_snapshot_threshold < 0)
|
|
return true;
|
|
else
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* lazy_truncate_heap - try to truncate off any empty pages at the end
|
|
*/
|
|
static void
|
|
lazy_truncate_heap(Relation onerel, LVRelStats *vacrelstats)
|
|
{
|
|
BlockNumber old_rel_pages = vacrelstats->rel_pages;
|
|
BlockNumber new_rel_pages;
|
|
int lock_retry;
|
|
|
|
/* Report that we are now truncating */
|
|
pgstat_progress_update_param(PROGRESS_VACUUM_PHASE,
|
|
PROGRESS_VACUUM_PHASE_TRUNCATE);
|
|
|
|
/*
|
|
* Loop until no more truncating can be done.
|
|
*/
|
|
do
|
|
{
|
|
PGRUsage ru0;
|
|
|
|
pg_rusage_init(&ru0);
|
|
|
|
/*
|
|
* We need full exclusive lock on the relation in order to do
|
|
* truncation. If we can't get it, give up rather than waiting --- we
|
|
* don't want to block other backends, and we don't want to deadlock
|
|
* (which is quite possible considering we already hold a lower-grade
|
|
* lock).
|
|
*/
|
|
vacrelstats->lock_waiter_detected = false;
|
|
lock_retry = 0;
|
|
while (true)
|
|
{
|
|
if (ConditionalLockRelation(onerel, AccessExclusiveLock))
|
|
break;
|
|
|
|
/*
|
|
* Check for interrupts while trying to (re-)acquire the exclusive
|
|
* lock.
|
|
*/
|
|
CHECK_FOR_INTERRUPTS();
|
|
|
|
if (++lock_retry > (VACUUM_TRUNCATE_LOCK_TIMEOUT /
|
|
VACUUM_TRUNCATE_LOCK_WAIT_INTERVAL))
|
|
{
|
|
/*
|
|
* We failed to establish the lock in the specified number of
|
|
* retries. This means we give up truncating.
|
|
*/
|
|
vacrelstats->lock_waiter_detected = true;
|
|
ereport(elevel,
|
|
(errmsg("\"%s\": stopping truncate due to conflicting lock request",
|
|
vacrelstats->relname)));
|
|
return;
|
|
}
|
|
|
|
pg_usleep(VACUUM_TRUNCATE_LOCK_WAIT_INTERVAL * 1000L);
|
|
}
|
|
|
|
/*
|
|
* Now that we have exclusive lock, look to see if the rel has grown
|
|
* whilst we were vacuuming with non-exclusive lock. If so, give up;
|
|
* the newly added pages presumably contain non-deletable tuples.
|
|
*/
|
|
new_rel_pages = RelationGetNumberOfBlocks(onerel);
|
|
if (new_rel_pages != old_rel_pages)
|
|
{
|
|
/*
|
|
* Note: we intentionally don't update vacrelstats->rel_pages with
|
|
* the new rel size here. If we did, it would amount to assuming
|
|
* that the new pages are empty, which is unlikely. Leaving the
|
|
* numbers alone amounts to assuming that the new pages have the
|
|
* same tuple density as existing ones, which is less unlikely.
|
|
*/
|
|
UnlockRelation(onerel, AccessExclusiveLock);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Scan backwards from the end to verify that the end pages actually
|
|
* contain no tuples. This is *necessary*, not optional, because
|
|
* other backends could have added tuples to these pages whilst we
|
|
* were vacuuming.
|
|
*/
|
|
new_rel_pages = count_nondeletable_pages(onerel, vacrelstats);
|
|
vacrelstats->blkno = new_rel_pages;
|
|
|
|
if (new_rel_pages >= old_rel_pages)
|
|
{
|
|
/* can't do anything after all */
|
|
UnlockRelation(onerel, AccessExclusiveLock);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Okay to truncate.
|
|
*/
|
|
RelationTruncate(onerel, new_rel_pages);
|
|
|
|
/*
|
|
* We can release the exclusive lock as soon as we have truncated.
|
|
* Other backends can't safely access the relation until they have
|
|
* processed the smgr invalidation that smgrtruncate sent out ... but
|
|
* that should happen as part of standard invalidation processing once
|
|
* they acquire lock on the relation.
|
|
*/
|
|
UnlockRelation(onerel, AccessExclusiveLock);
|
|
|
|
/*
|
|
* Update statistics. Here, it *is* correct to adjust rel_pages
|
|
* without also touching reltuples, since the tuple count wasn't
|
|
* changed by the truncation.
|
|
*/
|
|
vacrelstats->pages_removed += old_rel_pages - new_rel_pages;
|
|
vacrelstats->rel_pages = new_rel_pages;
|
|
|
|
ereport(elevel,
|
|
(errmsg("\"%s\": truncated %u to %u pages",
|
|
vacrelstats->relname,
|
|
old_rel_pages, new_rel_pages),
|
|
errdetail_internal("%s",
|
|
pg_rusage_show(&ru0))));
|
|
old_rel_pages = new_rel_pages;
|
|
} while (new_rel_pages > vacrelstats->nonempty_pages &&
|
|
vacrelstats->lock_waiter_detected);
|
|
}
|
|
|
|
/*
|
|
* Rescan end pages to verify that they are (still) empty of tuples.
|
|
*
|
|
* Returns number of nondeletable pages (last nonempty page + 1).
|
|
*/
|
|
static BlockNumber
|
|
count_nondeletable_pages(Relation onerel, LVRelStats *vacrelstats)
|
|
{
|
|
BlockNumber blkno;
|
|
BlockNumber prefetchedUntil;
|
|
instr_time starttime;
|
|
|
|
/* Initialize the starttime if we check for conflicting lock requests */
|
|
INSTR_TIME_SET_CURRENT(starttime);
|
|
|
|
/*
|
|
* Start checking blocks at what we believe relation end to be and move
|
|
* backwards. (Strange coding of loop control is needed because blkno is
|
|
* unsigned.) To make the scan faster, we prefetch a few blocks at a time
|
|
* in forward direction, so that OS-level readahead can kick in.
|
|
*/
|
|
blkno = vacrelstats->rel_pages;
|
|
StaticAssertStmt((PREFETCH_SIZE & (PREFETCH_SIZE - 1)) == 0,
|
|
"prefetch size must be power of 2");
|
|
prefetchedUntil = InvalidBlockNumber;
|
|
while (blkno > vacrelstats->nonempty_pages)
|
|
{
|
|
Buffer buf;
|
|
Page page;
|
|
OffsetNumber offnum,
|
|
maxoff;
|
|
bool hastup;
|
|
|
|
/*
|
|
* Check if another process requests a lock on our relation. We are
|
|
* holding an AccessExclusiveLock here, so they will be waiting. We
|
|
* only do this once per VACUUM_TRUNCATE_LOCK_CHECK_INTERVAL, and we
|
|
* only check if that interval has elapsed once every 32 blocks to
|
|
* keep the number of system calls and actual shared lock table
|
|
* lookups to a minimum.
|
|
*/
|
|
if ((blkno % 32) == 0)
|
|
{
|
|
instr_time currenttime;
|
|
instr_time elapsed;
|
|
|
|
INSTR_TIME_SET_CURRENT(currenttime);
|
|
elapsed = currenttime;
|
|
INSTR_TIME_SUBTRACT(elapsed, starttime);
|
|
if ((INSTR_TIME_GET_MICROSEC(elapsed) / 1000)
|
|
>= VACUUM_TRUNCATE_LOCK_CHECK_INTERVAL)
|
|
{
|
|
if (LockHasWaitersRelation(onerel, AccessExclusiveLock))
|
|
{
|
|
ereport(elevel,
|
|
(errmsg("\"%s\": suspending truncate due to conflicting lock request",
|
|
vacrelstats->relname)));
|
|
|
|
vacrelstats->lock_waiter_detected = true;
|
|
return blkno;
|
|
}
|
|
starttime = currenttime;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We don't insert a vacuum delay point here, because we have an
|
|
* exclusive lock on the table which we want to hold for as short a
|
|
* time as possible. We still need to check for interrupts however.
|
|
*/
|
|
CHECK_FOR_INTERRUPTS();
|
|
|
|
blkno--;
|
|
|
|
/* If we haven't prefetched this lot yet, do so now. */
|
|
if (prefetchedUntil > blkno)
|
|
{
|
|
BlockNumber prefetchStart;
|
|
BlockNumber pblkno;
|
|
|
|
prefetchStart = blkno & ~(PREFETCH_SIZE - 1);
|
|
for (pblkno = prefetchStart; pblkno <= blkno; pblkno++)
|
|
{
|
|
PrefetchBuffer(onerel, MAIN_FORKNUM, pblkno);
|
|
CHECK_FOR_INTERRUPTS();
|
|
}
|
|
prefetchedUntil = prefetchStart;
|
|
}
|
|
|
|
buf = ReadBufferExtended(onerel, MAIN_FORKNUM, blkno,
|
|
RBM_NORMAL, vac_strategy);
|
|
|
|
/* In this phase we only need shared access to the buffer */
|
|
LockBuffer(buf, BUFFER_LOCK_SHARE);
|
|
|
|
page = BufferGetPage(buf);
|
|
|
|
if (PageIsNew(page) || PageIsEmpty(page))
|
|
{
|
|
UnlockReleaseBuffer(buf);
|
|
continue;
|
|
}
|
|
|
|
hastup = false;
|
|
maxoff = PageGetMaxOffsetNumber(page);
|
|
for (offnum = FirstOffsetNumber;
|
|
offnum <= maxoff;
|
|
offnum = OffsetNumberNext(offnum))
|
|
{
|
|
ItemId itemid;
|
|
|
|
itemid = PageGetItemId(page, offnum);
|
|
|
|
/*
|
|
* Note: any non-unused item should be taken as a reason to keep
|
|
* this page. We formerly thought that DEAD tuples could be
|
|
* thrown away, but that's not so, because we'd not have cleaned
|
|
* out their index entries.
|
|
*/
|
|
if (ItemIdIsUsed(itemid))
|
|
{
|
|
hastup = true;
|
|
break; /* can stop scanning */
|
|
}
|
|
} /* scan along page */
|
|
|
|
UnlockReleaseBuffer(buf);
|
|
|
|
/* Done scanning if we found a tuple here */
|
|
if (hastup)
|
|
return blkno + 1;
|
|
}
|
|
|
|
/*
|
|
* If we fall out of the loop, all the previously-thought-to-be-empty
|
|
* pages still are; we need not bother to look at the last known-nonempty
|
|
* page.
|
|
*/
|
|
return vacrelstats->nonempty_pages;
|
|
}
|
|
|
|
/*
|
|
* Return the maximum number of dead tuples we can record.
|
|
*/
|
|
static long
|
|
compute_max_dead_tuples(BlockNumber relblocks, bool useindex)
|
|
{
|
|
long maxtuples;
|
|
int vac_work_mem = IsAutoVacuumWorkerProcess() &&
|
|
autovacuum_work_mem != -1 ?
|
|
autovacuum_work_mem : maintenance_work_mem;
|
|
|
|
if (useindex)
|
|
{
|
|
maxtuples = MAXDEADTUPLES(vac_work_mem * 1024L);
|
|
maxtuples = Min(maxtuples, INT_MAX);
|
|
maxtuples = Min(maxtuples, MAXDEADTUPLES(MaxAllocSize));
|
|
|
|
/* curious coding here to ensure the multiplication can't overflow */
|
|
if ((BlockNumber) (maxtuples / LAZY_ALLOC_TUPLES) > relblocks)
|
|
maxtuples = relblocks * LAZY_ALLOC_TUPLES;
|
|
|
|
/* stay sane if small maintenance_work_mem */
|
|
maxtuples = Max(maxtuples, MaxHeapTuplesPerPage);
|
|
}
|
|
else
|
|
maxtuples = MaxHeapTuplesPerPage;
|
|
|
|
return maxtuples;
|
|
}
|
|
|
|
/*
|
|
* lazy_space_alloc - space allocation decisions for lazy vacuum
|
|
*
|
|
* See the comments at the head of this file for rationale.
|
|
*/
|
|
static void
|
|
lazy_space_alloc(LVRelStats *vacrelstats, BlockNumber relblocks)
|
|
{
|
|
LVDeadTuples *dead_tuples = NULL;
|
|
long maxtuples;
|
|
|
|
maxtuples = compute_max_dead_tuples(relblocks, vacrelstats->useindex);
|
|
|
|
dead_tuples = (LVDeadTuples *) palloc(SizeOfDeadTuples(maxtuples));
|
|
dead_tuples->num_tuples = 0;
|
|
dead_tuples->max_tuples = (int) maxtuples;
|
|
|
|
vacrelstats->dead_tuples = dead_tuples;
|
|
}
|
|
|
|
/*
|
|
* lazy_record_dead_tuple - remember one deletable tuple
|
|
*/
|
|
static void
|
|
lazy_record_dead_tuple(LVDeadTuples *dead_tuples, ItemPointer itemptr)
|
|
{
|
|
/*
|
|
* The array shouldn't overflow under normal behavior, but perhaps it
|
|
* could if we are given a really small maintenance_work_mem. In that
|
|
* case, just forget the last few tuples (we'll get 'em next time).
|
|
*/
|
|
if (dead_tuples->num_tuples < dead_tuples->max_tuples)
|
|
{
|
|
dead_tuples->itemptrs[dead_tuples->num_tuples] = *itemptr;
|
|
dead_tuples->num_tuples++;
|
|
pgstat_progress_update_param(PROGRESS_VACUUM_NUM_DEAD_TUPLES,
|
|
dead_tuples->num_tuples);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* lazy_tid_reaped() -- is a particular tid deletable?
|
|
*
|
|
* This has the right signature to be an IndexBulkDeleteCallback.
|
|
*
|
|
* Assumes dead_tuples array is in sorted order.
|
|
*/
|
|
static bool
|
|
lazy_tid_reaped(ItemPointer itemptr, void *state)
|
|
{
|
|
LVDeadTuples *dead_tuples = (LVDeadTuples *) state;
|
|
ItemPointer res;
|
|
|
|
res = (ItemPointer) bsearch((void *) itemptr,
|
|
(void *) dead_tuples->itemptrs,
|
|
dead_tuples->num_tuples,
|
|
sizeof(ItemPointerData),
|
|
vac_cmp_itemptr);
|
|
|
|
return (res != NULL);
|
|
}
|
|
|
|
/*
|
|
* Comparator routines for use with qsort() and bsearch().
|
|
*/
|
|
static int
|
|
vac_cmp_itemptr(const void *left, const void *right)
|
|
{
|
|
BlockNumber lblk,
|
|
rblk;
|
|
OffsetNumber loff,
|
|
roff;
|
|
|
|
lblk = ItemPointerGetBlockNumber((ItemPointer) left);
|
|
rblk = ItemPointerGetBlockNumber((ItemPointer) right);
|
|
|
|
if (lblk < rblk)
|
|
return -1;
|
|
if (lblk > rblk)
|
|
return 1;
|
|
|
|
loff = ItemPointerGetOffsetNumber((ItemPointer) left);
|
|
roff = ItemPointerGetOffsetNumber((ItemPointer) right);
|
|
|
|
if (loff < roff)
|
|
return -1;
|
|
if (loff > roff)
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Check if every tuple in the given page is visible to all current and future
|
|
* transactions. Also return the visibility_cutoff_xid which is the highest
|
|
* xmin amongst the visible tuples. Set *all_frozen to true if every tuple
|
|
* on this page is frozen.
|
|
*/
|
|
static bool
|
|
heap_page_is_all_visible(Relation rel, Buffer buf,
|
|
LVRelStats *vacrelstats,
|
|
TransactionId *visibility_cutoff_xid,
|
|
bool *all_frozen)
|
|
{
|
|
Page page = BufferGetPage(buf);
|
|
BlockNumber blockno = BufferGetBlockNumber(buf);
|
|
OffsetNumber offnum,
|
|
maxoff;
|
|
bool all_visible = true;
|
|
|
|
*visibility_cutoff_xid = InvalidTransactionId;
|
|
*all_frozen = true;
|
|
|
|
/*
|
|
* This is a stripped down version of the line pointer scan in
|
|
* lazy_scan_heap(). So if you change anything here, also check that code.
|
|
*/
|
|
maxoff = PageGetMaxOffsetNumber(page);
|
|
for (offnum = FirstOffsetNumber;
|
|
offnum <= maxoff && all_visible;
|
|
offnum = OffsetNumberNext(offnum))
|
|
{
|
|
ItemId itemid;
|
|
HeapTupleData tuple;
|
|
|
|
/*
|
|
* Set the offset number so that we can display it along with any
|
|
* error that occurred while processing this tuple.
|
|
*/
|
|
vacrelstats->offnum = offnum;
|
|
itemid = PageGetItemId(page, offnum);
|
|
|
|
/* Unused or redirect line pointers are of no interest */
|
|
if (!ItemIdIsUsed(itemid) || ItemIdIsRedirected(itemid))
|
|
continue;
|
|
|
|
ItemPointerSet(&(tuple.t_self), blockno, offnum);
|
|
|
|
/*
|
|
* Dead line pointers can have index pointers pointing to them. So
|
|
* they can't be treated as visible
|
|
*/
|
|
if (ItemIdIsDead(itemid))
|
|
{
|
|
all_visible = false;
|
|
*all_frozen = false;
|
|
break;
|
|
}
|
|
|
|
Assert(ItemIdIsNormal(itemid));
|
|
|
|
tuple.t_data = (HeapTupleHeader) PageGetItem(page, itemid);
|
|
tuple.t_len = ItemIdGetLength(itemid);
|
|
tuple.t_tableOid = RelationGetRelid(rel);
|
|
|
|
switch (HeapTupleSatisfiesVacuum(&tuple, OldestXmin, buf))
|
|
{
|
|
case HEAPTUPLE_LIVE:
|
|
{
|
|
TransactionId xmin;
|
|
|
|
/* Check comments in lazy_scan_heap. */
|
|
if (!HeapTupleHeaderXminCommitted(tuple.t_data))
|
|
{
|
|
all_visible = false;
|
|
*all_frozen = false;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* The inserter definitely committed. But is it old enough
|
|
* that everyone sees it as committed?
|
|
*/
|
|
xmin = HeapTupleHeaderGetXmin(tuple.t_data);
|
|
if (!TransactionIdPrecedes(xmin, OldestXmin))
|
|
{
|
|
all_visible = false;
|
|
*all_frozen = false;
|
|
break;
|
|
}
|
|
|
|
/* Track newest xmin on page. */
|
|
if (TransactionIdFollows(xmin, *visibility_cutoff_xid))
|
|
*visibility_cutoff_xid = xmin;
|
|
|
|
/* Check whether this tuple is already frozen or not */
|
|
if (all_visible && *all_frozen &&
|
|
heap_tuple_needs_eventual_freeze(tuple.t_data))
|
|
*all_frozen = false;
|
|
}
|
|
break;
|
|
|
|
case HEAPTUPLE_DEAD:
|
|
case HEAPTUPLE_RECENTLY_DEAD:
|
|
case HEAPTUPLE_INSERT_IN_PROGRESS:
|
|
case HEAPTUPLE_DELETE_IN_PROGRESS:
|
|
{
|
|
all_visible = false;
|
|
*all_frozen = false;
|
|
break;
|
|
}
|
|
default:
|
|
elog(ERROR, "unexpected HeapTupleSatisfiesVacuum result");
|
|
break;
|
|
}
|
|
} /* scan along page */
|
|
|
|
/* Clear the offset information once we have processed the given page. */
|
|
vacrelstats->offnum = InvalidOffsetNumber;
|
|
|
|
return all_visible;
|
|
}
|
|
|
|
/*
|
|
* Compute the number of parallel worker processes to request. Both index
|
|
* vacuum and index cleanup can be executed with parallel workers. The index
|
|
* is eligible for parallel vacuum iff its size is greater than
|
|
* min_parallel_index_scan_size as invoking workers for very small indexes
|
|
* can hurt performance.
|
|
*
|
|
* nrequested is the number of parallel workers that user requested. If
|
|
* nrequested is 0, we compute the parallel degree based on nindexes, that is
|
|
* the number of indexes that support parallel vacuum. This function also
|
|
* sets can_parallel_vacuum to remember indexes that participate in parallel
|
|
* vacuum.
|
|
*/
|
|
static int
|
|
compute_parallel_vacuum_workers(Relation *Irel, int nindexes, int nrequested,
|
|
bool *can_parallel_vacuum)
|
|
{
|
|
int nindexes_parallel = 0;
|
|
int nindexes_parallel_bulkdel = 0;
|
|
int nindexes_parallel_cleanup = 0;
|
|
int parallel_workers;
|
|
int i;
|
|
|
|
/*
|
|
* We don't allow performing parallel operation in standalone backend or
|
|
* when parallelism is disabled.
|
|
*/
|
|
if (!IsUnderPostmaster || max_parallel_maintenance_workers == 0)
|
|
return 0;
|
|
|
|
/*
|
|
* Compute the number of indexes that can participate in parallel vacuum.
|
|
*/
|
|
for (i = 0; i < nindexes; i++)
|
|
{
|
|
uint8 vacoptions = Irel[i]->rd_indam->amparallelvacuumoptions;
|
|
|
|
if (vacoptions == VACUUM_OPTION_NO_PARALLEL ||
|
|
RelationGetNumberOfBlocks(Irel[i]) < min_parallel_index_scan_size)
|
|
continue;
|
|
|
|
can_parallel_vacuum[i] = true;
|
|
|
|
if ((vacoptions & VACUUM_OPTION_PARALLEL_BULKDEL) != 0)
|
|
nindexes_parallel_bulkdel++;
|
|
if (((vacoptions & VACUUM_OPTION_PARALLEL_CLEANUP) != 0) ||
|
|
((vacoptions & VACUUM_OPTION_PARALLEL_COND_CLEANUP) != 0))
|
|
nindexes_parallel_cleanup++;
|
|
}
|
|
|
|
nindexes_parallel = Max(nindexes_parallel_bulkdel,
|
|
nindexes_parallel_cleanup);
|
|
|
|
/* The leader process takes one index */
|
|
nindexes_parallel--;
|
|
|
|
/* No index supports parallel vacuum */
|
|
if (nindexes_parallel <= 0)
|
|
return 0;
|
|
|
|
/* Compute the parallel degree */
|
|
parallel_workers = (nrequested > 0) ?
|
|
Min(nrequested, nindexes_parallel) : nindexes_parallel;
|
|
|
|
/* Cap by max_parallel_maintenance_workers */
|
|
parallel_workers = Min(parallel_workers, max_parallel_maintenance_workers);
|
|
|
|
return parallel_workers;
|
|
}
|
|
|
|
/*
|
|
* Initialize variables for shared index statistics, set NULL bitmap and the
|
|
* size of stats for each index.
|
|
*/
|
|
static void
|
|
prepare_index_statistics(LVShared *lvshared, bool *can_parallel_vacuum,
|
|
int nindexes)
|
|
{
|
|
int i;
|
|
|
|
/* Currently, we don't support parallel vacuum for autovacuum */
|
|
Assert(!IsAutoVacuumWorkerProcess());
|
|
|
|
/* Set NULL for all indexes */
|
|
memset(lvshared->bitmap, 0x00, BITMAPLEN(nindexes));
|
|
|
|
for (i = 0; i < nindexes; i++)
|
|
{
|
|
if (!can_parallel_vacuum[i])
|
|
continue;
|
|
|
|
/* Set NOT NULL as this index does support parallelism */
|
|
lvshared->bitmap[i >> 3] |= 1 << (i & 0x07);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Update index statistics in pg_class if the statistics are accurate.
|
|
*/
|
|
static void
|
|
update_index_statistics(Relation *Irel, IndexBulkDeleteResult **stats,
|
|
int nindexes)
|
|
{
|
|
int i;
|
|
|
|
Assert(!IsInParallelMode());
|
|
|
|
for (i = 0; i < nindexes; i++)
|
|
{
|
|
if (stats[i] == NULL || stats[i]->estimated_count)
|
|
continue;
|
|
|
|
/* Update index statistics */
|
|
vac_update_relstats(Irel[i],
|
|
stats[i]->num_pages,
|
|
stats[i]->num_index_tuples,
|
|
0,
|
|
false,
|
|
InvalidTransactionId,
|
|
InvalidMultiXactId,
|
|
false);
|
|
pfree(stats[i]);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This function prepares and returns parallel vacuum state if we can launch
|
|
* even one worker. This function is responsible for entering parallel mode,
|
|
* create a parallel context, and then initialize the DSM segment.
|
|
*/
|
|
static LVParallelState *
|
|
begin_parallel_vacuum(Oid relid, Relation *Irel, LVRelStats *vacrelstats,
|
|
BlockNumber nblocks, int nindexes, int nrequested)
|
|
{
|
|
LVParallelState *lps = NULL;
|
|
ParallelContext *pcxt;
|
|
LVShared *shared;
|
|
LVDeadTuples *dead_tuples;
|
|
BufferUsage *buffer_usage;
|
|
WalUsage *wal_usage;
|
|
bool *can_parallel_vacuum;
|
|
long maxtuples;
|
|
char *sharedquery;
|
|
Size est_shared;
|
|
Size est_deadtuples;
|
|
int nindexes_mwm = 0;
|
|
int parallel_workers = 0;
|
|
int querylen;
|
|
int i;
|
|
|
|
/*
|
|
* A parallel vacuum must be requested and there must be indexes on the
|
|
* relation
|
|
*/
|
|
Assert(nrequested >= 0);
|
|
Assert(nindexes > 0);
|
|
|
|
/*
|
|
* Compute the number of parallel vacuum workers to launch
|
|
*/
|
|
can_parallel_vacuum = (bool *) palloc0(sizeof(bool) * nindexes);
|
|
parallel_workers = compute_parallel_vacuum_workers(Irel, nindexes,
|
|
nrequested,
|
|
can_parallel_vacuum);
|
|
|
|
/* Can't perform vacuum in parallel */
|
|
if (parallel_workers <= 0)
|
|
{
|
|
pfree(can_parallel_vacuum);
|
|
return lps;
|
|
}
|
|
|
|
lps = (LVParallelState *) palloc0(sizeof(LVParallelState));
|
|
|
|
EnterParallelMode();
|
|
pcxt = CreateParallelContext("postgres", "parallel_vacuum_main",
|
|
parallel_workers);
|
|
Assert(pcxt->nworkers > 0);
|
|
lps->pcxt = pcxt;
|
|
|
|
/* Estimate size for shared information -- PARALLEL_VACUUM_KEY_SHARED */
|
|
est_shared = MAXALIGN(add_size(SizeOfLVShared, BITMAPLEN(nindexes)));
|
|
for (i = 0; i < nindexes; i++)
|
|
{
|
|
uint8 vacoptions = Irel[i]->rd_indam->amparallelvacuumoptions;
|
|
|
|
/*
|
|
* Cleanup option should be either disabled, always performing in
|
|
* parallel or conditionally performing in parallel.
|
|
*/
|
|
Assert(((vacoptions & VACUUM_OPTION_PARALLEL_CLEANUP) == 0) ||
|
|
((vacoptions & VACUUM_OPTION_PARALLEL_COND_CLEANUP) == 0));
|
|
Assert(vacoptions <= VACUUM_OPTION_MAX_VALID_VALUE);
|
|
|
|
/* Skip indexes that don't participate in parallel vacuum */
|
|
if (!can_parallel_vacuum[i])
|
|
continue;
|
|
|
|
if (Irel[i]->rd_indam->amusemaintenanceworkmem)
|
|
nindexes_mwm++;
|
|
|
|
est_shared = add_size(est_shared, sizeof(LVSharedIndStats));
|
|
|
|
/*
|
|
* Remember the number of indexes that support parallel operation for
|
|
* each phase.
|
|
*/
|
|
if ((vacoptions & VACUUM_OPTION_PARALLEL_BULKDEL) != 0)
|
|
lps->nindexes_parallel_bulkdel++;
|
|
if ((vacoptions & VACUUM_OPTION_PARALLEL_CLEANUP) != 0)
|
|
lps->nindexes_parallel_cleanup++;
|
|
if ((vacoptions & VACUUM_OPTION_PARALLEL_COND_CLEANUP) != 0)
|
|
lps->nindexes_parallel_condcleanup++;
|
|
}
|
|
shm_toc_estimate_chunk(&pcxt->estimator, est_shared);
|
|
shm_toc_estimate_keys(&pcxt->estimator, 1);
|
|
|
|
/* Estimate size for dead tuples -- PARALLEL_VACUUM_KEY_DEAD_TUPLES */
|
|
maxtuples = compute_max_dead_tuples(nblocks, true);
|
|
est_deadtuples = MAXALIGN(SizeOfDeadTuples(maxtuples));
|
|
shm_toc_estimate_chunk(&pcxt->estimator, est_deadtuples);
|
|
shm_toc_estimate_keys(&pcxt->estimator, 1);
|
|
|
|
/*
|
|
* Estimate space for BufferUsage and WalUsage --
|
|
* PARALLEL_VACUUM_KEY_BUFFER_USAGE and PARALLEL_VACUUM_KEY_WAL_USAGE.
|
|
*
|
|
* If there are no extensions loaded that care, we could skip this. We
|
|
* have no way of knowing whether anyone's looking at pgBufferUsage or
|
|
* pgWalUsage, so do it unconditionally.
|
|
*/
|
|
shm_toc_estimate_chunk(&pcxt->estimator,
|
|
mul_size(sizeof(BufferUsage), pcxt->nworkers));
|
|
shm_toc_estimate_keys(&pcxt->estimator, 1);
|
|
shm_toc_estimate_chunk(&pcxt->estimator,
|
|
mul_size(sizeof(WalUsage), pcxt->nworkers));
|
|
shm_toc_estimate_keys(&pcxt->estimator, 1);
|
|
|
|
/* Finally, estimate PARALLEL_VACUUM_KEY_QUERY_TEXT space */
|
|
querylen = strlen(debug_query_string);
|
|
shm_toc_estimate_chunk(&pcxt->estimator, querylen + 1);
|
|
shm_toc_estimate_keys(&pcxt->estimator, 1);
|
|
|
|
InitializeParallelDSM(pcxt);
|
|
|
|
/* Prepare shared information */
|
|
shared = (LVShared *) shm_toc_allocate(pcxt->toc, est_shared);
|
|
MemSet(shared, 0, est_shared);
|
|
shared->relid = relid;
|
|
shared->elevel = elevel;
|
|
shared->maintenance_work_mem_worker =
|
|
(nindexes_mwm > 0) ?
|
|
maintenance_work_mem / Min(parallel_workers, nindexes_mwm) :
|
|
maintenance_work_mem;
|
|
|
|
pg_atomic_init_u32(&(shared->cost_balance), 0);
|
|
pg_atomic_init_u32(&(shared->active_nworkers), 0);
|
|
pg_atomic_init_u32(&(shared->idx), 0);
|
|
shared->offset = MAXALIGN(add_size(SizeOfLVShared, BITMAPLEN(nindexes)));
|
|
prepare_index_statistics(shared, can_parallel_vacuum, nindexes);
|
|
|
|
shm_toc_insert(pcxt->toc, PARALLEL_VACUUM_KEY_SHARED, shared);
|
|
lps->lvshared = shared;
|
|
|
|
/* Prepare the dead tuple space */
|
|
dead_tuples = (LVDeadTuples *) shm_toc_allocate(pcxt->toc, est_deadtuples);
|
|
dead_tuples->max_tuples = maxtuples;
|
|
dead_tuples->num_tuples = 0;
|
|
MemSet(dead_tuples->itemptrs, 0, sizeof(ItemPointerData) * maxtuples);
|
|
shm_toc_insert(pcxt->toc, PARALLEL_VACUUM_KEY_DEAD_TUPLES, dead_tuples);
|
|
vacrelstats->dead_tuples = dead_tuples;
|
|
|
|
/*
|
|
* Allocate space for each worker's BufferUsage and WalUsage; no need to
|
|
* initialize
|
|
*/
|
|
buffer_usage = shm_toc_allocate(pcxt->toc,
|
|
mul_size(sizeof(BufferUsage), pcxt->nworkers));
|
|
shm_toc_insert(pcxt->toc, PARALLEL_VACUUM_KEY_BUFFER_USAGE, buffer_usage);
|
|
lps->buffer_usage = buffer_usage;
|
|
wal_usage = shm_toc_allocate(pcxt->toc,
|
|
mul_size(sizeof(WalUsage), pcxt->nworkers));
|
|
shm_toc_insert(pcxt->toc, PARALLEL_VACUUM_KEY_WAL_USAGE, wal_usage);
|
|
lps->wal_usage = wal_usage;
|
|
|
|
/* Store query string for workers */
|
|
sharedquery = (char *) shm_toc_allocate(pcxt->toc, querylen + 1);
|
|
memcpy(sharedquery, debug_query_string, querylen + 1);
|
|
sharedquery[querylen] = '\0';
|
|
shm_toc_insert(pcxt->toc, PARALLEL_VACUUM_KEY_QUERY_TEXT, sharedquery);
|
|
|
|
pfree(can_parallel_vacuum);
|
|
return lps;
|
|
}
|
|
|
|
/*
|
|
* Destroy the parallel context, and end parallel mode.
|
|
*
|
|
* Since writes are not allowed during parallel mode, copy the
|
|
* updated index statistics from DSM into local memory and then later use that
|
|
* to update the index statistics. One might think that we can exit from
|
|
* parallel mode, update the index statistics and then destroy parallel
|
|
* context, but that won't be safe (see ExitParallelMode).
|
|
*/
|
|
static void
|
|
end_parallel_vacuum(IndexBulkDeleteResult **stats, LVParallelState *lps,
|
|
int nindexes)
|
|
{
|
|
int i;
|
|
|
|
Assert(!IsParallelWorker());
|
|
|
|
/* Copy the updated statistics */
|
|
for (i = 0; i < nindexes; i++)
|
|
{
|
|
LVSharedIndStats *indstats = get_indstats(lps->lvshared, i);
|
|
|
|
/*
|
|
* Skip unused slot. The statistics of this index are already stored
|
|
* in local memory.
|
|
*/
|
|
if (indstats == NULL)
|
|
continue;
|
|
|
|
if (indstats->updated)
|
|
{
|
|
stats[i] = (IndexBulkDeleteResult *) palloc0(sizeof(IndexBulkDeleteResult));
|
|
memcpy(stats[i], &(indstats->stats), sizeof(IndexBulkDeleteResult));
|
|
}
|
|
else
|
|
stats[i] = NULL;
|
|
}
|
|
|
|
DestroyParallelContext(lps->pcxt);
|
|
ExitParallelMode();
|
|
|
|
/* Deactivate parallel vacuum */
|
|
pfree(lps);
|
|
lps = NULL;
|
|
}
|
|
|
|
/* Return the Nth index statistics or NULL */
|
|
static LVSharedIndStats *
|
|
get_indstats(LVShared *lvshared, int n)
|
|
{
|
|
int i;
|
|
char *p;
|
|
|
|
if (IndStatsIsNull(lvshared, n))
|
|
return NULL;
|
|
|
|
p = (char *) GetSharedIndStats(lvshared);
|
|
for (i = 0; i < n; i++)
|
|
{
|
|
if (IndStatsIsNull(lvshared, i))
|
|
continue;
|
|
|
|
p += sizeof(LVSharedIndStats);
|
|
}
|
|
|
|
return (LVSharedIndStats *) p;
|
|
}
|
|
|
|
/*
|
|
* Returns true, if the given index can't participate in parallel index vacuum
|
|
* or parallel index cleanup, false, otherwise.
|
|
*/
|
|
static bool
|
|
skip_parallel_vacuum_index(Relation indrel, LVShared *lvshared)
|
|
{
|
|
uint8 vacoptions = indrel->rd_indam->amparallelvacuumoptions;
|
|
|
|
/* first_time must be true only if for_cleanup is true */
|
|
Assert(lvshared->for_cleanup || !lvshared->first_time);
|
|
|
|
if (lvshared->for_cleanup)
|
|
{
|
|
/* Skip, if the index does not support parallel cleanup */
|
|
if (((vacoptions & VACUUM_OPTION_PARALLEL_CLEANUP) == 0) &&
|
|
((vacoptions & VACUUM_OPTION_PARALLEL_COND_CLEANUP) == 0))
|
|
return true;
|
|
|
|
/*
|
|
* Skip, if the index supports parallel cleanup conditionally, but we
|
|
* have already processed the index (for bulkdelete). See the
|
|
* comments for option VACUUM_OPTION_PARALLEL_COND_CLEANUP to know
|
|
* when indexes support parallel cleanup conditionally.
|
|
*/
|
|
if (!lvshared->first_time &&
|
|
((vacoptions & VACUUM_OPTION_PARALLEL_COND_CLEANUP) != 0))
|
|
return true;
|
|
}
|
|
else if ((vacoptions & VACUUM_OPTION_PARALLEL_BULKDEL) == 0)
|
|
{
|
|
/* Skip if the index does not support parallel bulk deletion */
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Perform work within a launched parallel process.
|
|
*
|
|
* Since parallel vacuum workers perform only index vacuum or index cleanup,
|
|
* we don't need to report progress information.
|
|
*/
|
|
void
|
|
parallel_vacuum_main(dsm_segment *seg, shm_toc *toc)
|
|
{
|
|
Relation onerel;
|
|
Relation *indrels;
|
|
LVShared *lvshared;
|
|
LVDeadTuples *dead_tuples;
|
|
BufferUsage *buffer_usage;
|
|
WalUsage *wal_usage;
|
|
int nindexes;
|
|
char *sharedquery;
|
|
IndexBulkDeleteResult **stats;
|
|
LVRelStats vacrelstats;
|
|
ErrorContextCallback errcallback;
|
|
|
|
lvshared = (LVShared *) shm_toc_lookup(toc, PARALLEL_VACUUM_KEY_SHARED,
|
|
false);
|
|
elevel = lvshared->elevel;
|
|
|
|
ereport(DEBUG1,
|
|
(errmsg("starting parallel vacuum worker for %s",
|
|
lvshared->for_cleanup ? "cleanup" : "bulk delete")));
|
|
|
|
/* Set debug_query_string for individual workers */
|
|
sharedquery = shm_toc_lookup(toc, PARALLEL_VACUUM_KEY_QUERY_TEXT, false);
|
|
debug_query_string = sharedquery;
|
|
pgstat_report_activity(STATE_RUNNING, debug_query_string);
|
|
|
|
/*
|
|
* Open table. The lock mode is the same as the leader process. It's
|
|
* okay because the lock mode does not conflict among the parallel
|
|
* workers.
|
|
*/
|
|
onerel = table_open(lvshared->relid, ShareUpdateExclusiveLock);
|
|
|
|
/*
|
|
* Open all indexes. indrels are sorted in order by OID, which should be
|
|
* matched to the leader's one.
|
|
*/
|
|
vac_open_indexes(onerel, RowExclusiveLock, &nindexes, &indrels);
|
|
Assert(nindexes > 0);
|
|
|
|
/* Set dead tuple space */
|
|
dead_tuples = (LVDeadTuples *) shm_toc_lookup(toc,
|
|
PARALLEL_VACUUM_KEY_DEAD_TUPLES,
|
|
false);
|
|
|
|
/* Set cost-based vacuum delay */
|
|
VacuumCostActive = (VacuumCostDelay > 0);
|
|
VacuumCostBalance = 0;
|
|
VacuumPageHit = 0;
|
|
VacuumPageMiss = 0;
|
|
VacuumPageDirty = 0;
|
|
VacuumCostBalanceLocal = 0;
|
|
VacuumSharedCostBalance = &(lvshared->cost_balance);
|
|
VacuumActiveNWorkers = &(lvshared->active_nworkers);
|
|
|
|
stats = (IndexBulkDeleteResult **)
|
|
palloc0(nindexes * sizeof(IndexBulkDeleteResult *));
|
|
|
|
if (lvshared->maintenance_work_mem_worker > 0)
|
|
maintenance_work_mem = lvshared->maintenance_work_mem_worker;
|
|
|
|
/*
|
|
* Initialize vacrelstats for use as error callback arg by parallel
|
|
* worker.
|
|
*/
|
|
vacrelstats.relnamespace = get_namespace_name(RelationGetNamespace(onerel));
|
|
vacrelstats.relname = pstrdup(RelationGetRelationName(onerel));
|
|
vacrelstats.indname = NULL;
|
|
vacrelstats.phase = VACUUM_ERRCB_PHASE_UNKNOWN; /* Not yet processing */
|
|
|
|
/* Setup error traceback support for ereport() */
|
|
errcallback.callback = vacuum_error_callback;
|
|
errcallback.arg = &vacrelstats;
|
|
errcallback.previous = error_context_stack;
|
|
error_context_stack = &errcallback;
|
|
|
|
/* Prepare to track buffer usage during parallel execution */
|
|
InstrStartParallelQuery();
|
|
|
|
/* Process indexes to perform vacuum/cleanup */
|
|
parallel_vacuum_index(indrels, stats, lvshared, dead_tuples, nindexes,
|
|
&vacrelstats);
|
|
|
|
/* Report buffer/WAL usage during parallel execution */
|
|
buffer_usage = shm_toc_lookup(toc, PARALLEL_VACUUM_KEY_BUFFER_USAGE, false);
|
|
wal_usage = shm_toc_lookup(toc, PARALLEL_VACUUM_KEY_WAL_USAGE, false);
|
|
InstrEndParallelQuery(&buffer_usage[ParallelWorkerNumber],
|
|
&wal_usage[ParallelWorkerNumber]);
|
|
|
|
/* Pop the error context stack */
|
|
error_context_stack = errcallback.previous;
|
|
|
|
vac_close_indexes(nindexes, indrels, RowExclusiveLock);
|
|
table_close(onerel, ShareUpdateExclusiveLock);
|
|
pfree(stats);
|
|
}
|
|
|
|
/*
|
|
* Error context callback for errors occurring during vacuum.
|
|
*/
|
|
static void
|
|
vacuum_error_callback(void *arg)
|
|
{
|
|
LVRelStats *errinfo = arg;
|
|
|
|
switch (errinfo->phase)
|
|
{
|
|
case VACUUM_ERRCB_PHASE_SCAN_HEAP:
|
|
if (BlockNumberIsValid(errinfo->blkno))
|
|
{
|
|
if (OffsetNumberIsValid(errinfo->offnum))
|
|
errcontext("while scanning block %u and offset %u of relation \"%s.%s\"",
|
|
errinfo->blkno, errinfo->offnum, errinfo->relnamespace, errinfo->relname);
|
|
else
|
|
errcontext("while scanning block %u of relation \"%s.%s\"",
|
|
errinfo->blkno, errinfo->relnamespace, errinfo->relname);
|
|
}
|
|
else
|
|
errcontext("while scanning relation \"%s.%s\"",
|
|
errinfo->relnamespace, errinfo->relname);
|
|
break;
|
|
|
|
case VACUUM_ERRCB_PHASE_VACUUM_HEAP:
|
|
if (BlockNumberIsValid(errinfo->blkno))
|
|
{
|
|
if (OffsetNumberIsValid(errinfo->offnum))
|
|
errcontext("while vacuuming block %u and offset %u of relation \"%s.%s\"",
|
|
errinfo->blkno, errinfo->offnum, errinfo->relnamespace, errinfo->relname);
|
|
else
|
|
errcontext("while vacuuming block %u of relation \"%s.%s\"",
|
|
errinfo->blkno, errinfo->relnamespace, errinfo->relname);
|
|
}
|
|
else
|
|
errcontext("while vacuuming relation \"%s.%s\"",
|
|
errinfo->relnamespace, errinfo->relname);
|
|
break;
|
|
|
|
case VACUUM_ERRCB_PHASE_VACUUM_INDEX:
|
|
errcontext("while vacuuming index \"%s\" of relation \"%s.%s\"",
|
|
errinfo->indname, errinfo->relnamespace, errinfo->relname);
|
|
break;
|
|
|
|
case VACUUM_ERRCB_PHASE_INDEX_CLEANUP:
|
|
errcontext("while cleaning up index \"%s\" of relation \"%s.%s\"",
|
|
errinfo->indname, errinfo->relnamespace, errinfo->relname);
|
|
break;
|
|
|
|
case VACUUM_ERRCB_PHASE_TRUNCATE:
|
|
if (BlockNumberIsValid(errinfo->blkno))
|
|
errcontext("while truncating relation \"%s.%s\" to %u blocks",
|
|
errinfo->relnamespace, errinfo->relname, errinfo->blkno);
|
|
break;
|
|
|
|
case VACUUM_ERRCB_PHASE_UNKNOWN:
|
|
default:
|
|
return; /* do nothing; the errinfo may not be
|
|
* initialized */
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Updates the information required for vacuum error callback. This also saves
|
|
* the current information which can be later restored via restore_vacuum_error_info.
|
|
*/
|
|
static void
|
|
update_vacuum_error_info(LVRelStats *errinfo, LVSavedErrInfo *saved_err_info, int phase,
|
|
BlockNumber blkno, OffsetNumber offnum)
|
|
{
|
|
if (saved_err_info)
|
|
{
|
|
saved_err_info->offnum = errinfo->offnum;
|
|
saved_err_info->blkno = errinfo->blkno;
|
|
saved_err_info->phase = errinfo->phase;
|
|
}
|
|
|
|
errinfo->blkno = blkno;
|
|
errinfo->offnum = offnum;
|
|
errinfo->phase = phase;
|
|
}
|
|
|
|
/*
|
|
* Restores the vacuum information saved via a prior call to update_vacuum_error_info.
|
|
*/
|
|
static void
|
|
restore_vacuum_error_info(LVRelStats *errinfo, const LVSavedErrInfo *saved_err_info)
|
|
{
|
|
errinfo->blkno = saved_err_info->blkno;
|
|
errinfo->offnum = saved_err_info->offnum;
|
|
errinfo->phase = saved_err_info->phase;
|
|
}
|