Add database page inspection /contrib module.

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

View File

@ -1,4 +1,4 @@
# $PostgreSQL: pgsql/contrib/Makefile,v 1.75 2007/04/21 17:26:17 petere Exp $
# $PostgreSQL: pgsql/contrib/Makefile,v 1.76 2007/05/17 19:11:24 momjian Exp $
subdir = contrib
top_builddir = ..
@ -19,6 +19,7 @@ WANTED_DIRS = \
lo \
ltree \
oid2name \
pageinspect \
pg_buffercache \
pg_freespacemap \
pg_standby \

View File

@ -80,6 +80,10 @@ oid2name -
Maps numeric files to table names
by B Palmer <bpalmer@crimelabs.net>
pageinspect -
Allows inspection of database pages
Heikki Linnakangas <heikki@enterprisedb.com>
pg_buffercache -
Real time queries on the shared buffer cache
by Mark Kirkwood <markir@paradise.net.nz>

View File

@ -0,0 +1,24 @@
#-------------------------------------------------------------------------
#
# pageinspect Makefile
#
# $PostgreSQL: pgsql/contrib/pageinspect/Makefile,v 1.1 2007/05/17 19:11:24 momjian Exp $
#
#-------------------------------------------------------------------------
MODULE_big = pageinspect
OBJS = rawpage.o heapfuncs.o btreefuncs.o
DOCS = README.pageinspect
DATA_built = pageinspect.sql
DATA = uninstall_pageinspect.sql
ifdef USE_PGXS
PGXS := $(shell pg_config --pgxs)
include $(PGXS)
else
subdir = contrib/pageinspect
top_builddir = ../..
include $(top_builddir)/src/Makefile.global
include $(top_srcdir)/contrib/contrib-global.mk
endif

View File

@ -0,0 +1,94 @@
The functions in this module allow you to inspect the contents of data pages
at a low level, for debugging purposes.
1. Installation
$ make
$ make install
$ psql -e -f /usr/local/pgsql/share/contrib/pageinspect.sql test
2. Functions included:
get_raw_page
------------
get_raw_page reads one block of the named table and returns a copy as a
bytea field. This allows a single time-consistent copy of the block to be
made. Use of this functions is restricted to superusers.
page_header
-----------
page_header shows fields which are common to all PostgreSQL heap and index
pages. Use of this function is restricted to superusers.
A page image obtained with get_raw_page should be passed as argument:
test=# SELECT * FROM page_header(get_raw_page('pg_class',0));
lsn | tli | flags | lower | upper | special | pagesize | version
----------+-----+-------+-------+-------+---------+----------+---------
0/3C5614 | 1 | 1 | 216 | 256 | 8192 | 8192 | 4
(1 row)
The returned columns correspond to the fields in the PageHeaderData-struct,
see src/include/storage/bufpage.h for more details.
heap_page_items
---------------
heap_page_items shows all line pointers on a heap page. For those line
pointers that are in use, tuple headers are also shown. All tuples are
shown, whether or not the tuples were visible to an MVCC snapshot at the
time the raw page was copied. Use of this function is restricted to
superusers.
A heap page image obtained with get_raw_page should be passed as argument:
test=# SELECT * FROM heap_page_items(get_raw_page('pg_class',0));
See src/include/storage/itemid.h and src/include/access/htup.h for
explanations of the fields returned.
bt_metap
--------
bt_metap() returns information about the btree index metapage:
test=> SELECT * FROM bt_metap('pg_cast_oid_index');
-[ RECORD 1 ]-----
magic | 340322
version | 2
root | 1
level | 0
fastroot | 1
fastlevel | 0
bt_page_stats
-------------
bt_page_stats() shows information about single btree pages:
test=> SELECT * FROM bt_page_stats('pg_cast_oid_index', 1);
-[ RECORD 1 ]-+-----
blkno | 1
type | l
live_items | 256
dead_items | 0
avg_item_size | 12
page_size | 8192
free_size | 4056
btpo_prev | 0
btpo_next | 0
btpo | 0
btpo_flags | 3
bt_page_items
-------------
bt_page_items() returns information about specific items on btree pages:
test=> SELECT * FROM bt_page_items('pg_cast_oid_index', 1);
itemoffset | ctid | itemlen | nulls | vars | data
------------+---------+---------+-------+------+-------------
1 | (0,1) | 12 | f | f | 23 27 00 00
2 | (0,2) | 12 | f | f | 24 27 00 00
3 | (0,3) | 12 | f | f | 25 27 00 00
4 | (0,4) | 12 | f | f | 26 27 00 00
5 | (0,5) | 12 | f | f | 27 27 00 00
6 | (0,6) | 12 | f | f | 28 27 00 00
7 | (0,7) | 12 | f | f | 29 27 00 00
8 | (0,8) | 12 | f | f | 2a 27 00 00

View File

@ -0,0 +1,499 @@
/*
* 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);
}

View File

@ -0,0 +1,229 @@
/*-------------------------------------------------------------------------
*
* heapfuncs.c
* Functions to investigate heap pages
*
* We check the input to these functions for corrupt pointers etc. that
* might cause crashes, but at the same time we try to print out as much
* information as possible, even if it's nonsense. That's because if a
* page is corrupt, we don't know why and how exactly it is corrupt, so we
* let the user to judge it.
*
* These functions are restricted to superusers for the fear of introducing
* security holes if the input checking isn't as water-tight as it should.
* You'd need to be superuser to obtain a raw page image anyway, so
* there's hardly any use case for using these without superuser-rights
* anyway.
*
* Copyright (c) 2007, PostgreSQL Global Development Group
*
* IDENTIFICATION
* $PostgreSQL: pgsql/contrib/pageinspect/heapfuncs.c,v 1.1 2007/05/17 19:11:24 momjian Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "fmgr.h"
#include "funcapi.h"
#include "access/heapam.h"
#include "access/transam.h"
#include "catalog/namespace.h"
#include "catalog/pg_type.h"
#include "utils/builtins.h"
#include "miscadmin.h"
Datum heap_page_items(PG_FUNCTION_ARGS);
#define GET_TEXT(str_) \
DirectFunctionCall1(textin, CStringGetDatum(str_))
/*
* bits_to_text
*
* Converts a bits8-array of 'len' bits to a human-readable
* c-string representation.
*/
static char *
bits_to_text(bits8 *bits, int len)
{
int i;
char *str;
str = palloc(len + 1);
for(i = 0; i < len; i++)
str[i] = (bits[(i / 8)] & (1 << (i % 8))) ? '1' : '0';
str[i] = '\0';
return str;
}
/*
* heap_page_items
*
* Allows inspection of line pointers and tuple headers of a heap page.
*/
PG_FUNCTION_INFO_V1(heap_page_items);
typedef struct heap_page_items_state
{
TupleDesc tupd;
Page page;
uint16 offset;
} heap_page_items_state;
Datum
heap_page_items(PG_FUNCTION_ARGS)
{
bytea *raw_page = PG_GETARG_BYTEA_P(0);
heap_page_items_state *inter_call_data = NULL;
FuncCallContext *fctx;
int raw_page_size;
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
(errmsg("must be superuser to use raw page functions"))));
raw_page_size = VARSIZE(raw_page) - VARHDRSZ;
if (SRF_IS_FIRSTCALL())
{
TupleDesc tupdesc;
MemoryContext mctx;
if(raw_page_size < SizeOfPageHeaderData)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("input page too small (%d bytes)", raw_page_size)));
fctx = SRF_FIRSTCALL_INIT();
mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
inter_call_data = palloc(sizeof(heap_page_items_state));
/* Build a tuple descriptor for our result type */
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "return type must be a row type");
inter_call_data->tupd = tupdesc;
inter_call_data->offset = FirstOffsetNumber;
inter_call_data->page = VARDATA(raw_page);
fctx->max_calls = PageGetMaxOffsetNumber(inter_call_data->page);
fctx->user_fctx = inter_call_data;
MemoryContextSwitchTo(mctx);
}
fctx = SRF_PERCALL_SETUP();
inter_call_data = fctx->user_fctx;
if (fctx->call_cntr < fctx->max_calls)
{
Page page = inter_call_data->page;
HeapTuple resultTuple;
Datum result;
ItemId id;
Datum values[13];
bool nulls[13];
uint16 lp_offset;
uint16 lp_flags;
uint16 lp_len;
memset(nulls, 0, sizeof(nulls));
/* Extract information from the line pointer */
id = PageGetItemId(page, inter_call_data->offset);
lp_offset = ItemIdGetOffset(id);
lp_flags = ItemIdGetFlags(id);
lp_len = ItemIdGetLength(id);
values[0] = UInt16GetDatum(inter_call_data->offset);
values[1] = UInt16GetDatum(lp_offset);
values[2] = UInt16GetDatum(lp_flags);
values[3] = UInt16GetDatum(lp_len);
/* We do just enough validity checking to make sure we don't
* reference data outside the page passed to us. The page
* could be corrupt in many other ways, but at least we won't
* crash.
*/
if ((lp_len >= sizeof(HeapTupleHeader)) &&
(lp_offset == MAXALIGN(lp_offset)) &&
(lp_offset + lp_len <= raw_page_size) &&
ItemIdIsUsed(id))
{
HeapTupleHeader tuphdr;
int bits_len;
/* Extract infromation from the tuple header */
tuphdr = (HeapTupleHeader) PageGetItem(page, id);
values[4] = UInt32GetDatum(HeapTupleHeaderGetXmin(tuphdr));
values[5] = UInt32GetDatum(HeapTupleHeaderGetXmax(tuphdr));
values[6] = UInt32GetDatum(HeapTupleHeaderGetRawCommandId(tuphdr)); /* shared with xvac */
values[7] = PointerGetDatum(&tuphdr->t_ctid);
values[8] = UInt16GetDatum(tuphdr->t_infomask2);
values[9] = UInt16GetDatum(tuphdr->t_infomask);
values[10] = UInt8GetDatum(tuphdr->t_hoff);
/* We already checked that the item as is completely within
* the raw page passed to us, with the length given in the line
* pointer.. Let's check that t_hoff doesn't point over lp_len,
* before using it to access t_bits and oid.
*/
if (tuphdr->t_hoff >= sizeof(HeapTupleHeader) &&
tuphdr->t_hoff <= lp_len)
{
if (tuphdr->t_infomask & HEAP_HASNULL)
{
bits_len = tuphdr->t_hoff -
(((char *)tuphdr->t_bits) - ((char *)tuphdr));
values[11] = GET_TEXT(
bits_to_text(tuphdr->t_bits, bits_len * 8));
}
else
nulls[11] = true;
if (tuphdr->t_infomask & HEAP_HASOID)
values[12] = HeapTupleHeaderGetOid(tuphdr);
else
nulls[12] = true;
}
else
{
nulls[11] = true;
nulls[12] = true;
}
}
else
{
/* The line pointer is not used, or it's invalid. Set the rest of
* the fields to NULL */
int i;
for(i = 4; i <= 12; i++)
nulls[i] = true;
}
/* Build and return the result tuple. */
resultTuple = heap_form_tuple(inter_call_data->tupd, values, nulls);
result = HeapTupleGetDatum(resultTuple);
inter_call_data->offset++;
SRF_RETURN_NEXT(fctx, result);
}
else
SRF_RETURN_DONE(fctx);
}

View File

@ -0,0 +1,109 @@
-- Adjust this setting to control where the objects get created.
SET search_path = public;
--
-- get_raw_page()
--
CREATE OR REPLACE FUNCTION get_raw_page(text, int4)
RETURNS bytea
AS 'MODULE_PATHNAME', 'get_raw_page'
LANGUAGE C STRICT;
--
-- page_header()
--
CREATE TYPE page_header_type AS (
lsn text,
tli smallint,
flags smallint,
lower smallint,
upper smallint,
special smallint,
pagesize smallint,
version smallint
);
CREATE OR REPLACE FUNCTION page_header(bytea)
RETURNS page_header_type
AS 'MODULE_PATHNAME', 'page_header'
LANGUAGE C STRICT;
--
-- heap_page_items()
--
CREATE TYPE heap_page_items_type AS (
lp smallint,
lp_off smallint,
lp_flags smallint,
lp_len smallint,
t_xmin xid,
t_xmax xid,
t_field3 int4,
t_ctid tid,
t_infomask2 smallint,
t_infomask smallint,
t_hoff smallint,
t_bits text,
t_oid oid
);
CREATE OR REPLACE FUNCTION heap_page_items(bytea)
RETURNS SETOF heap_page_items_type
AS 'MODULE_PATHNAME', 'heap_page_items'
LANGUAGE C STRICT;
--
-- bt_metap()
--
CREATE TYPE bt_metap_type AS (
magic int4,
version int4,
root int4,
level int4,
fastroot int4,
fastlevel int4
);
CREATE OR REPLACE FUNCTION bt_metap(text)
RETURNS bt_metap_type
AS 'MODULE_PATHNAME', 'bt_metap'
LANGUAGE 'C' STRICT;
--
-- bt_page_stats()
--
CREATE TYPE bt_page_stats_type AS (
blkno int4,
type char,
live_items int4,
dead_items int4,
avg_item_size float,
page_size int4,
free_size int4,
btpo_prev int4,
btpo_next int4,
btpo int4,
btpo_flags int4
);
CREATE OR REPLACE FUNCTION bt_page_stats(text, int4)
RETURNS bt_page_stats_type
AS 'MODULE_PATHNAME', 'bt_page_stats'
LANGUAGE 'C' STRICT;
--
-- bt_page_items()
--
CREATE TYPE bt_page_items_type AS (
itemoffset smallint,
ctid tid,
itemlen smallint,
nulls bool,
vars bool,
data text
);
CREATE OR REPLACE FUNCTION bt_page_items(text, int4)
RETURNS SETOF bt_page_items_type
AS 'MODULE_PATHNAME', 'bt_page_items'
LANGUAGE 'C' STRICT;

View File

@ -0,0 +1,164 @@
/*-------------------------------------------------------------------------
*
* rawpage.c
* Functions to extract a raw page as bytea and inspect it
*
* Access-method specific inspection functions are in separate files.
*
* Copyright (c) 2007, PostgreSQL Global Development Group
*
* IDENTIFICATION
* $PostgreSQL: pgsql/contrib/pageinspect/rawpage.c,v 1.1 2007/05/17 19:11:24 momjian Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "fmgr.h"
#include "funcapi.h"
#include "access/heapam.h"
#include "access/transam.h"
#include "catalog/namespace.h"
#include "catalog/pg_type.h"
#include "utils/builtins.h"
#include "miscadmin.h"
PG_MODULE_MAGIC;
Datum get_raw_page(PG_FUNCTION_ARGS);
Datum page_header(PG_FUNCTION_ARGS);
/*
* get_raw_page
*
* Returns a copy of a page from shared buffers as a bytea
*/
PG_FUNCTION_INFO_V1(get_raw_page);
Datum
get_raw_page(PG_FUNCTION_ARGS)
{
text *relname = PG_GETARG_TEXT_P(0);
uint32 blkno = PG_GETARG_UINT32(1);
Relation rel;
RangeVar *relrv;
bytea *raw_page;
char *raw_page_data;
Buffer buf;
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
(errmsg("must be superuser to use raw functions"))));
relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
rel = relation_openrv(relrv, AccessShareLock);
/* Check that this relation has storage */
if (rel->rd_rel->relkind == RELKIND_VIEW)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot get raw page from view \"%s\"",
RelationGetRelationName(rel))));
if (rel->rd_rel->relkind == RELKIND_COMPOSITE_TYPE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("cannot get raw page from composite type \"%s\"",
RelationGetRelationName(rel))));
if (blkno >= RelationGetNumberOfBlocks(rel))
elog(ERROR, "block number %u is out of range for relation \"%s\"",
blkno, RelationGetRelationName(rel));
/* Initialize buffer to copy to */
raw_page = (bytea *) palloc(BLCKSZ + VARHDRSZ);
SET_VARSIZE(raw_page, BLCKSZ + VARHDRSZ);
raw_page_data = VARDATA(raw_page);
/* Take a verbatim copy of the page */
buf = ReadBuffer(rel, blkno);
LockBuffer(buf, BUFFER_LOCK_SHARE);
memcpy(raw_page_data, BufferGetPage(buf), BLCKSZ);
LockBuffer(buf, BUFFER_LOCK_UNLOCK);
ReleaseBuffer(buf);
relation_close(rel, AccessShareLock);
PG_RETURN_BYTEA_P(raw_page);
}
/*
* page_header
*
* Allows inspection of page header fields of a raw page
*/
PG_FUNCTION_INFO_V1(page_header);
Datum
page_header(PG_FUNCTION_ARGS)
{
bytea *raw_page = PG_GETARG_BYTEA_P(0);
int raw_page_size;
TupleDesc tupdesc;
Datum result;
HeapTuple tuple;
Datum values[8];
bool nulls[8];
PageHeader page;
XLogRecPtr lsn;
char lsnchar[64];
if (!superuser())
ereport(ERROR,
(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
(errmsg("must be superuser to use raw page functions"))));
raw_page_size = VARSIZE(raw_page) - VARHDRSZ;
/*
* Check that enough data was supplied, so that we don't try to access
* fields outside the supplied buffer.
*/
if(raw_page_size < sizeof(PageHeaderData))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("input page too small (%d bytes)", raw_page_size)));
page = (PageHeader) VARDATA(raw_page);
/* Build a tuple descriptor for our result type */
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "return type must be a row type");
/* Extract information from the page header */
lsn = PageGetLSN(page);
snprintf(lsnchar, sizeof(lsnchar), "%X/%X", lsn.xlogid, lsn.xrecoff);
values[0] = DirectFunctionCall1(textin, CStringGetDatum(lsnchar));
values[1] = UInt16GetDatum(PageGetTLI(page));
values[2] = UInt16GetDatum(page->pd_flags);
values[3] = UInt16GetDatum(page->pd_lower);
values[4] = UInt16GetDatum(page->pd_upper);
values[5] = UInt16GetDatum(page->pd_special);
values[6] = UInt16GetDatum(PageGetPageSize(page));
values[7] = UInt16GetDatum(PageGetPageLayoutVersion(page));
/* Build and return the tuple. */
memset(nulls, 0, sizeof(nulls));
tuple = heap_form_tuple(tupdesc, values, nulls);
result = HeapTupleGetDatum(tuple);
PG_RETURN_DATUM(result);
}

View File

@ -0,0 +1,20 @@
-- Adjust this setting to control where the objects get created.
SET search_path = public;
DROP FUNCTION get_raw_page(text, int4);
DROP FUNCTION page_header(bytea);
DROP TYPE page_header_type;
DROP FUNCTION heap_page_items(bytea);
DROP TYPE heap_page_items_type;
DROP FUNCTION bt_metap(text);
DROP TYPE bt_metap_type;
DROP FUNCTION bt_page_stats(text, int4);
DROP TYPE bt_page_stats_type;
DROP FUNCTION bt_page_items(text, int4);
DROP TYPE bt_page_items_type;

View File

@ -56,53 +56,6 @@ pgstattuple README 2002/08/29 Tatsuo Ishii
avg_leaf_density | 50.27
leaf_fragmentation | 0
bt_metap
--------
bt_metap() returns information about the btree index metapage:
test=> SELECT * FROM bt_metap('pg_cast_oid_index');
-[ RECORD 1 ]-----
magic | 340322
version | 2
root | 1
level | 0
fastroot | 1
fastlevel | 0
bt_page_stats
-------------
bt_page_stats() shows information about single btree pages:
test=> SELECT * FROM bt_page_stats('pg_cast_oid_index', 1);
-[ RECORD 1 ]-+-----
blkno | 1
type | l
live_items | 256
dead_items | 0
avg_item_size | 12
page_size | 8192
free_size | 4056
btpo_prev | 0
btpo_next | 0
btpo | 0
btpo_flags | 3
bt_page_items
-------------
bt_page_items() returns information about specific items on btree pages:
test=> SELECT * FROM bt_page_items('pg_cast_oid_index', 1);
itemoffset | ctid | itemlen | nulls | vars | data
------------+---------+---------+-------+------+-------------
1 | (0,1) | 12 | f | f | 23 27 00 00
2 | (0,2) | 12 | f | f | 24 27 00 00
3 | (0,3) | 12 | f | f | 25 27 00 00
4 | (0,4) | 12 | f | f | 26 27 00 00
5 | (0,5) | 12 | f | f | 27 27 00 00
6 | (0,6) | 12 | f | f | 28 27 00 00
7 | (0,7) | 12 | f | f | 29 27 00 00
8 | (0,8) | 12 | f | f | 2a 27 00 00
2. Installing pgstattuple
@ -140,6 +93,10 @@ pgstattuple README 2002/08/29 Tatsuo Ishii
5. History
2007/05/17
Moved page-level functions to contrib/pageinspect
2006/06/28
Extended to work against indexes.

View File

@ -36,30 +36,14 @@
#include "utils/inval.h"
PG_FUNCTION_INFO_V1(pgstatindex);
PG_FUNCTION_INFO_V1(bt_metap);
PG_FUNCTION_INFO_V1(bt_page_items);
PG_FUNCTION_INFO_V1(bt_page_stats);
PG_FUNCTION_INFO_V1(pg_relpages);
extern Datum pgstatindex(PG_FUNCTION_ARGS);
extern Datum bt_metap(PG_FUNCTION_ARGS);
extern Datum bt_page_items(PG_FUNCTION_ARGS);
extern Datum bt_page_stats(PG_FUNCTION_ARGS);
extern Datum pg_relpages(PG_FUNCTION_ARGS);
#define PGSTATINDEX_TYPE "public.pgstatindex_type"
#define PGSTATINDEX_NCOLUMNS 10
#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)
@ -72,34 +56,6 @@ extern Datum pg_relpages(PG_FUNCTION_ARGS);
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;
uint32 fragments;
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().
@ -107,116 +63,22 @@ typedef struct BTPageStat
*/
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;
uint32 fragments;
} 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->fragments = 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;
/*----------------------------------------------
* If a next leaf is on the previous block,
* it means a fragmentation.
*----------------------------------------------
*/
if (stat->type == 'l')
{
if (opaque->btpo_next != P_NONE && opaque->btpo_next < blkno)
stat->fragments++;
}
/* 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;
}
/* ------------------------------------------------------
* pgstatindex()
*
@ -249,12 +111,9 @@ pgstatindex(PG_FUNCTION_ARGS)
Page page = BufferGetPage(buffer);
BTMetaPageData *metad = BTPageGetMeta(page);
indexStat.magic = metad->btm_magic;
indexStat.version = metad->btm_version;
indexStat.root_blkno = metad->btm_root;
indexStat.level = metad->btm_level;
indexStat.fastroot = metad->btm_fastroot;
indexStat.fastlevel = metad->btm_fastlevel;
ReleaseBuffer(buffer);
}
@ -279,47 +138,49 @@ pgstatindex(PG_FUNCTION_ARGS)
*/
for (blkno = 1; blkno < nblocks; blkno++)
{
Buffer buffer = ReadBuffer(rel, blkno);
BTPageStat stat;
Buffer buffer;
Page page;
BTPageOpaque opaque;
/* scan one page */
stat.blkno = blkno;
GetBTPageStatistics(blkno, buffer, &stat);
/* Read and lock buffer */
buffer = ReadBuffer(rel, blkno);
LockBuffer(buffer, BUFFER_LOCK_SHARE);
/*---------------------
* page status (type)
*---------------------
*/
switch (stat.type)
page = BufferGetPage(buffer);
opaque = (BTPageOpaque) PageGetSpecialPointer(page);
/* Determine page type, and update totals */
if (P_ISDELETED(opaque))
indexStat.deleted_pages++;
else if (P_IGNORE(opaque))
indexStat.empty_pages++;
else if (P_ISLEAF(opaque))
{
case 'd':
indexStat.deleted_pages++;
break;
case 'l':
indexStat.leaf_pages++;
break;
case 'i':
indexStat.internal_pages++;
break;
case 'e':
indexStat.empty_pages++;
break;
case 'r':
indexStat.root_pages++;
break;
default:
elog(ERROR, "unknown page status.");
int max_avail;
max_avail = BLCKSZ - (BLCKSZ - ((PageHeader)page)->pd_special + SizeOfPageHeaderData);
indexStat.max_avail += max_avail;
indexStat.free_space += PageGetFreeSpace(page);
indexStat.leaf_pages++;
/*
* If the next leaf is on an earlier block, it
* means a fragmentation.
*/
if (opaque->btpo_next != P_NONE && opaque->btpo_next < blkno)
indexStat.fragments++;
}
else if (P_ISROOT(opaque))
indexStat.root_pages++;
/* -- leaf fragmentation -- */
indexStat.fragments += stat.fragments;
if (stat.type == 'l')
{
indexStat.max_avail += stat.max_avail;
indexStat.free_space += stat.free_size;
}
else
indexStat.internal_pages++;
/* Unlock and release buffer */
LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
ReleaseBuffer(buffer);
}
@ -373,305 +234,6 @@ pgstatindex(PG_FUNCTION_ARGS)
PG_RETURN_DATUM(result);
}
/* -----------------------------------------------
* 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;
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);
}
/* --------------------------------------------------------
* pg_relpages()
*

View File

@ -44,62 +44,6 @@ RETURNS pgstatindex_type
AS 'MODULE_PATHNAME', 'pgstatindex'
LANGUAGE 'C' STRICT;
--
-- bt_metap()
--
CREATE TYPE bt_metap_type AS (
magic int4,
version int4,
root int4,
level int4,
fastroot int4,
fastlevel int4
);
CREATE OR REPLACE FUNCTION bt_metap(text)
RETURNS bt_metap_type
AS 'MODULE_PATHNAME', 'bt_metap'
LANGUAGE 'C' STRICT;
--
-- bt_page_stats()
--
CREATE TYPE bt_page_stats_type AS (
blkno int4,
type char,
live_items int4,
dead_items int4,
avg_item_size float,
page_size int4,
free_size int4,
btpo_prev int4,
btpo_next int4,
btpo int4,
btpo_flags int4
);
CREATE OR REPLACE FUNCTION bt_page_stats(text, int4)
RETURNS bt_page_stats_type
AS 'MODULE_PATHNAME', 'bt_page_stats'
LANGUAGE 'C' STRICT;
--
-- bt_page_items()
--
CREATE TYPE bt_page_items_type AS (
itemoffset int4,
ctid tid,
itemlen int4,
nulls bool,
vars bool,
data text
);
CREATE OR REPLACE FUNCTION bt_page_items(text, int4)
RETURNS SETOF bt_page_items_type
AS 'MODULE_PATHNAME', 'bt_page_items'
LANGUAGE 'C' STRICT;
--
-- pg_relpages()
--

View File

@ -8,13 +8,4 @@ DROP TYPE pgstattuple_type;
DROP FUNCTION pgstatindex(text);
DROP TYPE pgstatindex_type;
DROP FUNCTION bt_metap(text);
DROP TYPE bt_metap_type;
DROP FUNCTION bt_page_stats(text, int4);
DROP TYPE bt_page_stats_type;
DROP FUNCTION bt_page_items(text, int4);
DROP TYPE bt_page_items_type;
DROP FUNCTION pg_relpages(text);