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tableam: relation creation, VACUUM FULL/CLUSTER, SET TABLESPACE.

This moves the responsibility for:
- creating the storage necessary for a relation, including creating a
  new relfilenode for a relation with existing storage
- non-transactional truncation of a relation
- VACUUM FULL / CLUSTER's rewrite of a table
below tableam.

This is fairly straight forward, with a bit of complexity smattered in
to move the computation of xid / multixid horizons below the AM, as
they don't make sense for every table AM.

Author: Andres Freund
Discussion: https://postgr.es/m/20180703070645.wchpu5muyto5n647@alap3.anarazel.de
This commit is contained in:
Andres Freund
2019-03-28 20:01:14 -07:00
parent 7e69323bf7
commit d25f519107
13 changed files with 856 additions and 579 deletions

View File

@ -23,16 +23,32 @@
#include "access/genam.h"
#include "access/heapam.h"
#include "access/multixact.h"
#include "access/rewriteheap.h"
#include "access/tableam.h"
#include "access/xact.h"
#include "catalog/catalog.h"
#include "catalog/index.h"
#include "catalog/storage.h"
#include "catalog/storage_xlog.h"
#include "commands/progress.h"
#include "executor/executor.h"
#include "pgstat.h"
#include "storage/bufmgr.h"
#include "storage/bufpage.h"
#include "storage/bufmgr.h"
#include "storage/lmgr.h"
#include "storage/predicate.h"
#include "storage/procarray.h"
#include "storage/smgr.h"
#include "utils/builtins.h"
#include "utils/rel.h"
static void
reform_and_rewrite_tuple(HeapTuple tuple,
Relation OldHeap, Relation NewHeap,
Datum *values, bool *isnull, RewriteState rwstate);
static const TableAmRoutine heapam_methods;
@ -523,6 +539,388 @@ tuple_lock_retry:
* ------------------------------------------------------------------------
*/
static void
heapam_relation_set_new_filenode(Relation rel, char persistence,
TransactionId *freezeXid,
MultiXactId *minmulti)
{
/*
* Initialize to the minimum XID that could put tuples in the table. We
* know that no xacts older than RecentXmin are still running, so that
* will do.
*/
*freezeXid = RecentXmin;
/*
* Similarly, initialize the minimum Multixact to the first value that
* could possibly be stored in tuples in the table. Running transactions
* could reuse values from their local cache, so we are careful to
* consider all currently running multis.
*
* XXX this could be refined further, but is it worth the hassle?
*/
*minmulti = GetOldestMultiXactId();
RelationCreateStorage(rel->rd_node, persistence);
/*
* If required, set up an init fork for an unlogged table so that it can
* be correctly reinitialized on restart. An immediate sync is required
* even if the page has been logged, because the write did not go through
* shared_buffers and therefore a concurrent checkpoint may have moved the
* redo pointer past our xlog record. Recovery may as well remove it
* while replaying, for example, XLOG_DBASE_CREATE or XLOG_TBLSPC_CREATE
* record. Therefore, logging is necessary even if wal_level=minimal.
*/
if (rel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED)
{
Assert(rel->rd_rel->relkind == RELKIND_RELATION ||
rel->rd_rel->relkind == RELKIND_MATVIEW ||
rel->rd_rel->relkind == RELKIND_TOASTVALUE);
RelationOpenSmgr(rel);
smgrcreate(rel->rd_smgr, INIT_FORKNUM, false);
log_smgrcreate(&rel->rd_smgr->smgr_rnode.node, INIT_FORKNUM);
smgrimmedsync(rel->rd_smgr, INIT_FORKNUM);
}
}
static void
heapam_relation_nontransactional_truncate(Relation rel)
{
RelationTruncate(rel, 0);
}
static void
heapam_relation_copy_data(Relation rel, RelFileNode newrnode)
{
SMgrRelation dstrel;
dstrel = smgropen(newrnode, rel->rd_backend);
RelationOpenSmgr(rel);
/*
* Create and copy all forks of the relation, and schedule unlinking of
* old physical files.
*
* NOTE: any conflict in relfilenode value will be caught in
* RelationCreateStorage().
*/
RelationCreateStorage(newrnode, rel->rd_rel->relpersistence);
/* copy main fork */
RelationCopyStorage(rel->rd_smgr, dstrel, MAIN_FORKNUM,
rel->rd_rel->relpersistence);
/* copy those extra forks that exist */
for (ForkNumber forkNum = MAIN_FORKNUM + 1;
forkNum <= MAX_FORKNUM; forkNum++)
{
if (smgrexists(rel->rd_smgr, forkNum))
{
smgrcreate(dstrel, forkNum, false);
/*
* WAL log creation if the relation is persistent, or this is the
* init fork of an unlogged relation.
*/
if (rel->rd_rel->relpersistence == RELPERSISTENCE_PERMANENT ||
(rel->rd_rel->relpersistence == RELPERSISTENCE_UNLOGGED &&
forkNum == INIT_FORKNUM))
log_smgrcreate(&newrnode, forkNum);
RelationCopyStorage(rel->rd_smgr, dstrel, forkNum,
rel->rd_rel->relpersistence);
}
}
/* drop old relation, and close new one */
RelationDropStorage(rel);
smgrclose(dstrel);
}
static void
heapam_relation_copy_for_cluster(Relation OldHeap, Relation NewHeap,
Relation OldIndex, bool use_sort,
TransactionId OldestXmin,
TransactionId FreezeXid,
MultiXactId MultiXactCutoff,
double *num_tuples,
double *tups_vacuumed,
double *tups_recently_dead)
{
RewriteState rwstate;
IndexScanDesc indexScan;
TableScanDesc tableScan;
HeapScanDesc heapScan;
bool use_wal;
bool is_system_catalog;
Tuplesortstate *tuplesort;
TupleDesc oldTupDesc = RelationGetDescr(OldHeap);
TupleDesc newTupDesc = RelationGetDescr(NewHeap);
TupleTableSlot *slot;
int natts;
Datum *values;
bool *isnull;
BufferHeapTupleTableSlot *hslot;
/* Remember if it's a system catalog */
is_system_catalog = IsSystemRelation(OldHeap);
/*
* We need to log the copied data in WAL iff WAL archiving/streaming is
* enabled AND it's a WAL-logged rel.
*/
use_wal = XLogIsNeeded() && RelationNeedsWAL(NewHeap);
/* use_wal off requires smgr_targblock be initially invalid */
Assert(RelationGetTargetBlock(NewHeap) == InvalidBlockNumber);
/* Preallocate values/isnull arrays */
natts = newTupDesc->natts;
values = (Datum *) palloc(natts * sizeof(Datum));
isnull = (bool *) palloc(natts * sizeof(bool));
/* Initialize the rewrite operation */
rwstate = begin_heap_rewrite(OldHeap, NewHeap, OldestXmin, FreezeXid,
MultiXactCutoff, use_wal);
/* Set up sorting if wanted */
if (use_sort)
tuplesort = tuplesort_begin_cluster(oldTupDesc, OldIndex,
maintenance_work_mem,
NULL, false);
else
tuplesort = NULL;
/*
* Prepare to scan the OldHeap. To ensure we see recently-dead tuples
* that still need to be copied, we scan with SnapshotAny and use
* HeapTupleSatisfiesVacuum for the visibility test.
*/
if (OldIndex != NULL && !use_sort)
{
const int ci_index[] = {
PROGRESS_CLUSTER_PHASE,
PROGRESS_CLUSTER_INDEX_RELID
};
int64 ci_val[2];
/* Set phase and OIDOldIndex to columns */
ci_val[0] = PROGRESS_CLUSTER_PHASE_INDEX_SCAN_HEAP;
ci_val[1] = RelationGetRelid(OldIndex);
pgstat_progress_update_multi_param(2, ci_index, ci_val);
tableScan = NULL;
heapScan = NULL;
indexScan = index_beginscan(OldHeap, OldIndex, SnapshotAny, 0, 0);
index_rescan(indexScan, NULL, 0, NULL, 0);
}
else
{
/* In scan-and-sort mode and also VACUUM FULL, set phase */
pgstat_progress_update_param(PROGRESS_CLUSTER_PHASE,
PROGRESS_CLUSTER_PHASE_SEQ_SCAN_HEAP);
tableScan = table_beginscan(OldHeap, SnapshotAny, 0, (ScanKey) NULL);
heapScan = (HeapScanDesc) tableScan;
indexScan = NULL;
/* Set total heap blocks */
pgstat_progress_update_param(PROGRESS_CLUSTER_TOTAL_HEAP_BLKS,
heapScan->rs_nblocks);
}
slot = table_slot_create(OldHeap, NULL);
hslot = (BufferHeapTupleTableSlot *) slot;
/*
* Scan through the OldHeap, either in OldIndex order or sequentially;
* copy each tuple into the NewHeap, or transiently to the tuplesort
* module. Note that we don't bother sorting dead tuples (they won't get
* to the new table anyway).
*/
for (;;)
{
HeapTuple tuple;
Buffer buf;
bool isdead;
CHECK_FOR_INTERRUPTS();
if (indexScan != NULL)
{
if (!index_getnext_slot(indexScan, ForwardScanDirection, slot))
break;
/* Since we used no scan keys, should never need to recheck */
if (indexScan->xs_recheck)
elog(ERROR, "CLUSTER does not support lossy index conditions");
}
else
{
if (!table_scan_getnextslot(tableScan, ForwardScanDirection, slot))
break;
/* In scan-and-sort mode and also VACUUM FULL, set heap blocks scanned */
pgstat_progress_update_param(PROGRESS_CLUSTER_HEAP_BLKS_SCANNED,
heapScan->rs_cblock + 1);
}
tuple = ExecFetchSlotHeapTuple(slot, false, NULL);
buf = hslot->buffer;
LockBuffer(buf, BUFFER_LOCK_SHARE);
switch (HeapTupleSatisfiesVacuum(tuple, OldestXmin, buf))
{
case HEAPTUPLE_DEAD:
/* Definitely dead */
isdead = true;
break;
case HEAPTUPLE_RECENTLY_DEAD:
*tups_recently_dead += 1;
/* fall through */
case HEAPTUPLE_LIVE:
/* Live or recently dead, must copy it */
isdead = false;
break;
case HEAPTUPLE_INSERT_IN_PROGRESS:
/*
* Since we hold exclusive lock on the relation, normally the
* only way to see this is if it was inserted earlier in our
* own transaction. However, it can happen in system
* catalogs, since we tend to release write lock before commit
* there. Give a warning if neither case applies; but in any
* case we had better copy it.
*/
if (!is_system_catalog &&
!TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(tuple->t_data)))
elog(WARNING, "concurrent insert in progress within table \"%s\"",
RelationGetRelationName(OldHeap));
/* treat as live */
isdead = false;
break;
case HEAPTUPLE_DELETE_IN_PROGRESS:
/*
* Similar situation to INSERT_IN_PROGRESS case.
*/
if (!is_system_catalog &&
!TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetUpdateXid(tuple->t_data)))
elog(WARNING, "concurrent delete in progress within table \"%s\"",
RelationGetRelationName(OldHeap));
/* treat as recently dead */
*tups_recently_dead += 1;
isdead = false;
break;
default:
elog(ERROR, "unexpected HeapTupleSatisfiesVacuum result");
isdead = false; /* keep compiler quiet */
break;
}
LockBuffer(buf, BUFFER_LOCK_UNLOCK);
if (isdead)
{
*tups_vacuumed += 1;
/* heap rewrite module still needs to see it... */
if (rewrite_heap_dead_tuple(rwstate, tuple))
{
/* A previous recently-dead tuple is now known dead */
*tups_vacuumed += 1;
*tups_recently_dead -= 1;
}
continue;
}
*num_tuples += 1;
if (tuplesort != NULL)
{
tuplesort_putheaptuple(tuplesort, tuple);
/* In scan-and-sort mode, report increase in number of tuples scanned */
pgstat_progress_update_param(PROGRESS_CLUSTER_HEAP_TUPLES_SCANNED,
*num_tuples);
}
else
{
const int ct_index[] = {
PROGRESS_CLUSTER_HEAP_TUPLES_SCANNED,
PROGRESS_CLUSTER_HEAP_TUPLES_WRITTEN
};
int64 ct_val[2];
reform_and_rewrite_tuple(tuple, OldHeap, NewHeap,
values, isnull, rwstate);
/*
* In indexscan mode and also VACUUM FULL, report increase in
* number of tuples scanned and written
*/
ct_val[0] = *num_tuples;
ct_val[1] = *num_tuples;
pgstat_progress_update_multi_param(2, ct_index, ct_val);
}
}
if (indexScan != NULL)
index_endscan(indexScan);
if (tableScan != NULL)
table_endscan(tableScan);
if (slot)
ExecDropSingleTupleTableSlot(slot);
/*
* In scan-and-sort mode, complete the sort, then read out all live tuples
* from the tuplestore and write them to the new relation.
*/
if (tuplesort != NULL)
{
double n_tuples = 0;
/* Report that we are now sorting tuples */
pgstat_progress_update_param(PROGRESS_CLUSTER_PHASE,
PROGRESS_CLUSTER_PHASE_SORT_TUPLES);
tuplesort_performsort(tuplesort);
/* Report that we are now writing new heap */
pgstat_progress_update_param(PROGRESS_CLUSTER_PHASE,
PROGRESS_CLUSTER_PHASE_WRITE_NEW_HEAP);
for (;;)
{
HeapTuple tuple;
CHECK_FOR_INTERRUPTS();
tuple = tuplesort_getheaptuple(tuplesort, true);
if (tuple == NULL)
break;
n_tuples += 1;
reform_and_rewrite_tuple(tuple,
OldHeap, NewHeap,
values, isnull,
rwstate);
/* Report n_tuples */
pgstat_progress_update_param(PROGRESS_CLUSTER_HEAP_TUPLES_WRITTEN,
n_tuples);
}
tuplesort_end(tuplesort);
}
/* Write out any remaining tuples, and fsync if needed */
end_heap_rewrite(rwstate);
/* Clean up */
pfree(values);
pfree(isnull);
}
static double
heapam_index_build_range_scan(Relation heapRelation,
Relation indexRelation,
@ -1256,6 +1654,55 @@ heapam_index_validate_scan(Relation heapRelation,
}
/* ----------------------------------------------------------------------------
* Helper functions for the above.
* ----------------------------------------------------------------------------
*/
/*
* Reconstruct and rewrite the given tuple
*
* We cannot simply copy the tuple as-is, for several reasons:
*
* 1. We'd like to squeeze out the values of any dropped columns, both
* to save space and to ensure we have no corner-case failures. (It's
* possible for example that the new table hasn't got a TOAST table
* and so is unable to store any large values of dropped cols.)
*
* 2. The tuple might not even be legal for the new table; this is
* currently only known to happen as an after-effect of ALTER TABLE
* SET WITHOUT OIDS.
*
* So, we must reconstruct the tuple from component Datums.
*/
static void
reform_and_rewrite_tuple(HeapTuple tuple,
Relation OldHeap, Relation NewHeap,
Datum *values, bool *isnull, RewriteState rwstate)
{
TupleDesc oldTupDesc = RelationGetDescr(OldHeap);
TupleDesc newTupDesc = RelationGetDescr(NewHeap);
HeapTuple copiedTuple;
int i;
heap_deform_tuple(tuple, oldTupDesc, values, isnull);
/* Be sure to null out any dropped columns */
for (i = 0; i < newTupDesc->natts; i++)
{
if (TupleDescAttr(newTupDesc, i)->attisdropped)
isnull[i] = true;
}
copiedTuple = heap_form_tuple(newTupDesc, values, isnull);
/* The heap rewrite module does the rest */
rewrite_heap_tuple(rwstate, tuple, copiedTuple);
heap_freetuple(copiedTuple);
}
/* ------------------------------------------------------------------------
* Definition of the heap table access method.
* ------------------------------------------------------------------------
@ -1292,6 +1739,10 @@ static const TableAmRoutine heapam_methods = {
.tuple_satisfies_snapshot = heapam_tuple_satisfies_snapshot,
.compute_xid_horizon_for_tuples = heap_compute_xid_horizon_for_tuples,
.relation_set_new_filenode = heapam_relation_set_new_filenode,
.relation_nontransactional_truncate = heapam_relation_nontransactional_truncate,
.relation_copy_data = heapam_relation_copy_data,
.relation_copy_for_cluster = heapam_relation_copy_for_cluster,
.index_build_range_scan = heapam_index_build_range_scan,
.index_validate_scan = heapam_index_validate_scan,
};