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Add database page inspection /contrib module.

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Simon and Heikki
This commit is contained in:
Bruce Momjian
2007-05-17 19:11:25 +00:00
parent 3b0347b36e
commit 64058429c5
13 changed files with 1186 additions and 588 deletions
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contrib/pageinspect/btreefuncs.c Normal file
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/*
* btreefuncs.c
*
* Copyright (c) 2006 Satoshi Nagayasu <nagayasus@nttdata.co.jp>
*
* Permission to use, copy, modify, and distribute this software and
* its documentation for any purpose, without fee, and without a
* written agreement is hereby granted, provided that the above
* copyright notice and this paragraph and the following two
* paragraphs appear in all copies.
*
* IN NO EVENT SHALL THE AUTHOR BE LIABLE TO ANY PARTY FOR DIRECT,
* INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES, INCLUDING
* LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
* DOCUMENTATION, EVEN IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
* THE AUTHOR SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS
* IS" BASIS, AND THE AUTHOR HAS NO OBLIGATIONS TO PROVIDE MAINTENANCE,
* SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*/
#include "postgres.h"
#include "fmgr.h"
#include "funcapi.h"
#include "access/heapam.h"
#include "access/itup.h"
#include "access/nbtree.h"
#include "access/transam.h"
#include "catalog/namespace.h"
#include "catalog/pg_type.h"
#include "utils/builtins.h"
#include "utils/inval.h"
PG_FUNCTION_INFO_V1(bt_metap);
PG_FUNCTION_INFO_V1(bt_page_items);
PG_FUNCTION_INFO_V1(bt_page_stats);
extern Datum bt_metap(PG_FUNCTION_ARGS);
extern Datum bt_page_items(PG_FUNCTION_ARGS);
extern Datum bt_page_stats(PG_FUNCTION_ARGS);
#define BTMETAP_TYPE "public.bt_metap_type"
#define BTMETAP_NCOLUMNS 6
#define BTPAGEITEMS_TYPE "public.bt_page_items_type"
#define BTPAGEITEMS_NCOLUMNS 6
#define BTPAGESTATS_TYPE "public.bt_page_stats_type"
#define BTPAGESTATS_NCOLUMNS 11
#define IS_INDEX(r) ((r)->rd_rel->relkind == 'i')
#define IS_BTREE(r) ((r)->rd_rel->relam == BTREE_AM_OID)
#define CHECK_PAGE_OFFSET_RANGE(page, offset) { \
if ( !(FirstOffsetNumber<=(offset) && \
(offset)<=PageGetMaxOffsetNumber(page)) ) \
elog(ERROR, "Page offset number out of range."); }
#define CHECK_RELATION_BLOCK_RANGE(rel, blkno) { \
if ( (blkno)<0 && RelationGetNumberOfBlocks((rel))<=(blkno) ) \
elog(ERROR, "Block number out of range."); }
/* ------------------------------------------------
* structure for single btree page statistics
* ------------------------------------------------
*/
typedef struct BTPageStat
{
uint32 blkno;
uint32 live_items;
uint32 dead_items;
uint32 page_size;
uint32 max_avail;
uint32 free_size;
uint32 avg_item_size;
char type;
/* opaque data */
BlockNumber btpo_prev;
BlockNumber btpo_next;
union
{
uint32 level;
TransactionId xact;
} btpo;
uint16 btpo_flags;
BTCycleId btpo_cycleid;
} BTPageStat;
/* ------------------------------------------------
* A structure for a whole btree index statistics
* used by pgstatindex().
* ------------------------------------------------
*/
typedef struct BTIndexStat
{
uint32 magic;
uint32 version;
BlockNumber root_blkno;
uint32 level;
BlockNumber fastroot;
uint32 fastlevel;
uint32 live_items;
uint32 dead_items;
uint32 root_pages;
uint32 internal_pages;
uint32 leaf_pages;
uint32 empty_pages;
uint32 deleted_pages;
uint32 page_size;
uint32 avg_item_size;
uint32 max_avail;
uint32 free_space;
} BTIndexStat;
/* -------------------------------------------------
* GetBTPageStatistics()
*
* Collect statistics of single b-tree leaf page
* -------------------------------------------------
*/
static void
GetBTPageStatistics(BlockNumber blkno, Buffer buffer, BTPageStat * stat)
{
Page page = BufferGetPage(buffer);
PageHeader phdr = (PageHeader) page;
OffsetNumber maxoff = PageGetMaxOffsetNumber(page);
BTPageOpaque opaque = (BTPageOpaque) PageGetSpecialPointer(page);
int item_size = 0;
int off;
stat->blkno = blkno;
stat->max_avail = BLCKSZ - (BLCKSZ - phdr->pd_special + SizeOfPageHeaderData);
stat->dead_items = stat->live_items = 0;
stat->page_size = PageGetPageSize(page);
/* page type (flags) */
if (P_ISDELETED(opaque))
{
stat->type = 'd';
stat->btpo.xact = opaque->btpo.xact;
return;
}
else if (P_IGNORE(opaque))
stat->type = 'e';
else if (P_ISLEAF(opaque))
stat->type = 'l';
else if (P_ISROOT(opaque))
stat->type = 'r';
else
stat->type = 'i';
/* btpage opaque data */
stat->btpo_prev = opaque->btpo_prev;
stat->btpo_next = opaque->btpo_next;
stat->btpo.level = opaque->btpo.level;
stat->btpo_flags = opaque->btpo_flags;
stat->btpo_cycleid = opaque->btpo_cycleid;
/* count live and dead tuples, and free space */
for (off = FirstOffsetNumber; off <= maxoff; off++)
{
IndexTuple itup;
ItemId id = PageGetItemId(page, off);
itup = (IndexTuple) PageGetItem(page, id);
item_size += IndexTupleSize(itup);
if (!ItemIdDeleted(id))
stat->live_items++;
else
stat->dead_items++;
}
stat->free_size = PageGetFreeSpace(page);
if ((stat->live_items + stat->dead_items) > 0)
stat->avg_item_size = item_size / (stat->live_items + stat->dead_items);
else
stat->avg_item_size = 0;
}
/* -----------------------------------------------
* bt_page()
*
* Usage: SELECT * FROM bt_page('t1_pkey', 0);
* -----------------------------------------------
*/
Datum
bt_page_stats(PG_FUNCTION_ARGS)
{
text *relname = PG_GETARG_TEXT_P(0);
uint32 blkno = PG_GETARG_UINT32(1);
Buffer buffer;
Relation rel;
RangeVar *relrv;
Datum result;
relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
rel = relation_openrv(relrv, AccessShareLock);
CHECK_RELATION_BLOCK_RANGE(rel, blkno);
buffer = ReadBuffer(rel, blkno);
if (!IS_INDEX(rel) || !IS_BTREE(rel))
elog(ERROR, "bt_page_stats() can be used only on b-tree index.");
if (blkno == 0)
elog(ERROR, "Block 0 is a meta page.");
{
HeapTuple tuple;
TupleDesc tupleDesc;
int j;
char *values[BTPAGESTATS_NCOLUMNS];
BTPageStat stat;
/* keep compiler quiet */
stat.btpo_prev = stat.btpo_next = InvalidBlockNumber;
stat.btpo_flags = stat.free_size = stat.avg_item_size = 0;
GetBTPageStatistics(blkno, buffer, &stat);
tupleDesc = RelationNameGetTupleDesc(BTPAGESTATS_TYPE);
j = 0;
values[j] = palloc(32);
snprintf(values[j++], 32, "%d", stat.blkno);
values[j] = palloc(32);
snprintf(values[j++], 32, "%c", stat.type);
values[j] = palloc(32);
snprintf(values[j++], 32, "%d", stat.live_items);
values[j] = palloc(32);
snprintf(values[j++], 32, "%d", stat.dead_items);
values[j] = palloc(32);
snprintf(values[j++], 32, "%d", stat.avg_item_size);
values[j] = palloc(32);
snprintf(values[j++], 32, "%d", stat.page_size);
values[j] = palloc(32);
snprintf(values[j++], 32, "%d", stat.free_size);
values[j] = palloc(32);
snprintf(values[j++], 32, "%d", stat.btpo_prev);
values[j] = palloc(32);
snprintf(values[j++], 32, "%d", stat.btpo_next);
values[j] = palloc(32);
if (stat.type == 'd')
snprintf(values[j++], 32, "%d", stat.btpo.xact);
else
snprintf(values[j++], 32, "%d", stat.btpo.level);
values[j] = palloc(32);
snprintf(values[j++], 32, "%d", stat.btpo_flags);
tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(tupleDesc),
values);
result = TupleGetDatum(TupleDescGetSlot(tupleDesc), tuple);
}
ReleaseBuffer(buffer);
relation_close(rel, AccessShareLock);
PG_RETURN_DATUM(result);
}
/*-------------------------------------------------------
* bt_page_items()
*
* Get IndexTupleData set in a leaf page
*
* Usage: SELECT * FROM bt_page_items('t1_pkey', 0);
*-------------------------------------------------------
*/
/* ---------------------------------------------------
* data structure for SRF to hold a scan information
* ---------------------------------------------------
*/
struct user_args
{
TupleDesc tupd;
Relation rel;
Buffer buffer;
Page page;
uint16 offset;
};
Datum
bt_page_items(PG_FUNCTION_ARGS)
{
text *relname = PG_GETARG_TEXT_P(0);
uint32 blkno = PG_GETARG_UINT32(1);
RangeVar *relrv;
Datum result;
char *values[BTPAGEITEMS_NCOLUMNS];
BTPageOpaque opaque;
HeapTuple tuple;
ItemId id;
FuncCallContext *fctx;
MemoryContext mctx;
struct user_args *uargs = NULL;
if (blkno == 0)
elog(ERROR, "Block 0 is a meta page.");
if (SRF_IS_FIRSTCALL())
{
fctx = SRF_FIRSTCALL_INIT();
mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
uargs = palloc(sizeof(struct user_args));
uargs->tupd = RelationNameGetTupleDesc(BTPAGEITEMS_TYPE);
uargs->offset = FirstOffsetNumber;
relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
uargs->rel = relation_openrv(relrv, AccessShareLock);
CHECK_RELATION_BLOCK_RANGE(uargs->rel, blkno);
uargs->buffer = ReadBuffer(uargs->rel, blkno);
if (!IS_INDEX(uargs->rel) || !IS_BTREE(uargs->rel))
elog(ERROR, "bt_page_items() can be used only on b-tree index.");
uargs->page = BufferGetPage(uargs->buffer);
opaque = (BTPageOpaque) PageGetSpecialPointer(uargs->page);
if (P_ISDELETED(opaque))
elog(NOTICE, "bt_page_items(): this page is deleted.");
fctx->max_calls = PageGetMaxOffsetNumber(uargs->page);
fctx->user_fctx = uargs;
MemoryContextSwitchTo(mctx);
}
fctx = SRF_PERCALL_SETUP();
uargs = fctx->user_fctx;
if (fctx->call_cntr < fctx->max_calls)
{
IndexTuple itup;
id = PageGetItemId(uargs->page, uargs->offset);
if (!ItemIdIsValid(id))
elog(ERROR, "Invalid ItemId.");
itup = (IndexTuple) PageGetItem(uargs->page, id);
{
int j = 0;
BlockNumber blkno = BlockIdGetBlockNumber(&(itup->t_tid.ip_blkid));
values[j] = palloc(32);
snprintf(values[j++], 32, "%d", uargs->offset);
values[j] = palloc(32);
snprintf(values[j++], 32, "(%u,%u)", blkno, itup->t_tid.ip_posid);
values[j] = palloc(32);
snprintf(values[j++], 32, "%d", (int) IndexTupleSize(itup));
values[j] = palloc(32);
snprintf(values[j++], 32, "%c", IndexTupleHasNulls(itup) ? 't' : 'f');
values[j] = palloc(32);
snprintf(values[j++], 32, "%c", IndexTupleHasVarwidths(itup) ? 't' : 'f');
{
int off;
char *dump;
char *ptr = (char *) itup + IndexInfoFindDataOffset(itup->t_info);
dump = palloc(IndexTupleSize(itup) * 3);
memset(dump, 0, IndexTupleSize(itup) * 3);
for (off = 0;
off < IndexTupleSize(itup) - IndexInfoFindDataOffset(itup->t_info);
off++)
{
if (dump[0] == '\0')
sprintf(dump, "%02x", *(ptr + off) & 0xff);
else
{
char buf[4];
sprintf(buf, " %02x", *(ptr + off) & 0xff);
strcat(dump, buf);
}
}
values[j] = dump;
}
tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(uargs->tupd), values);
result = TupleGetDatum(TupleDescGetSlot(uargs->tupd), tuple);
}
uargs->offset = uargs->offset + 1;
SRF_RETURN_NEXT(fctx, result);
}
else
{
ReleaseBuffer(uargs->buffer);
relation_close(uargs->rel, AccessShareLock);
SRF_RETURN_DONE(fctx);
}
}
/* ------------------------------------------------
* bt_metap()
*
* Get a btree meta-page information
*
* Usage: SELECT * FROM bt_metap('t1_pkey')
* ------------------------------------------------
*/
Datum
bt_metap(PG_FUNCTION_ARGS)
{
text *relname = PG_GETARG_TEXT_P(0);
Buffer buffer;
Relation rel;
RangeVar *relrv;
Datum result;
relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
rel = relation_openrv(relrv, AccessShareLock);
if (!IS_INDEX(rel) || !IS_BTREE(rel))
elog(ERROR, "bt_metap() can be used only on b-tree index.");
buffer = ReadBuffer(rel, 0);
{
BTMetaPageData *metad;
TupleDesc tupleDesc;
int j;
char *values[BTMETAP_NCOLUMNS];
HeapTuple tuple;
Page page = BufferGetPage(buffer);
metad = BTPageGetMeta(page);
tupleDesc = RelationNameGetTupleDesc(BTMETAP_TYPE);
j = 0;
values[j] = palloc(32);
snprintf(values[j++], 32, "%d", metad->btm_magic);
values[j] = palloc(32);
snprintf(values[j++], 32, "%d", metad->btm_version);
values[j] = palloc(32);
snprintf(values[j++], 32, "%d", metad->btm_root);
values[j] = palloc(32);
snprintf(values[j++], 32, "%d", metad->btm_level);
values[j] = palloc(32);
snprintf(values[j++], 32, "%d", metad->btm_fastroot);
values[j] = palloc(32);
snprintf(values[j++], 32, "%d", metad->btm_fastlevel);
tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(tupleDesc),
values);
result = TupleGetDatum(TupleDescGetSlot(tupleDesc), tuple);
}
ReleaseBuffer(buffer);
relation_close(rel, AccessShareLock);
PG_RETURN_DATUM(result);
}