Add pageinspect functions for inspecting GIN indexes.

Patch by me, Peter Geoghegan and Michael Paquier, reviewed by Amit Kapila.
This commit is contained in:
Heikki Linnakangas 2014-11-21 11:46:50 +02:00
parent adbfab119b
commit 3a82bc6f8a
5 changed files with 451 additions and 4 deletions

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@ -1,12 +1,13 @@
# contrib/pageinspect/Makefile
MODULE_big = pageinspect
OBJS = rawpage.o heapfuncs.o btreefuncs.o fsmfuncs.o brinfuncs.o $(WIN32RES)
OBJS = rawpage.o heapfuncs.o btreefuncs.o fsmfuncs.o \
brinfuncs.o ginfuncs.o $(WIN32RES)
EXTENSION = pageinspect
DATA = pageinspect--1.3.sql pageinspect--1.0--1.1.sql \
pageinspect--1.2--1.3.sql \
pageinspect--1.1--1.2.sql pageinspect--unpackaged--1.0.sql
DATA = pageinspect--1.3.sql pageinspect--1.2--1.3.sql \
pageinspect--1.1--1.2.sql pageinspect--1.0--1.1.sql \
pageinspect--unpackaged--1.0.sql
PGFILEDESC = "pageinspect - functions to inspect contents of database pages"
ifdef USE_PGXS

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@ -0,0 +1,281 @@
/*
* ginfuncs.c
* Functions to investigate the content of GIN indexes
*
* Copyright (c) 2014, PostgreSQL Global Development Group
*
* IDENTIFICATION
* contrib/pageinspect/ginfuncs.c
*/
#include "postgres.h"
#include "access/gin.h"
#include "access/gin_private.h"
#include "access/htup_details.h"
#include "catalog/namespace.h"
#include "catalog/pg_type.h"
#include "funcapi.h"
#include "miscadmin.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/rel.h"
#define DatumGetItemPointer(X) ((ItemPointer) DatumGetPointer(X))
#define ItemPointerGetDatum(X) PointerGetDatum(X)
PG_FUNCTION_INFO_V1(gin_metapage_info);
PG_FUNCTION_INFO_V1(gin_page_opaque_info);
PG_FUNCTION_INFO_V1(gin_leafpage_items);
Datum
gin_metapage_info(PG_FUNCTION_ARGS)
{
bytea *raw_page = PG_GETARG_BYTEA_P(0);
int raw_page_size;
TupleDesc tupdesc;
Page page;
GinPageOpaque opaq;
GinMetaPageData *metadata;
HeapTuple resultTuple;
Datum values[10];
bool nulls[10];
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 (raw_page_size < BLCKSZ)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("input page too small (%d bytes)", raw_page_size)));
page = VARDATA(raw_page);
opaq = (GinPageOpaque) PageGetSpecialPointer(page);
if (opaq->flags != GIN_META)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("input page is not a GIN metapage"),
errdetail("Flags %04X, expected %04X",
opaq->flags, GIN_META)));
/* 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");
metadata = GinPageGetMeta(page);
memset(nulls, 0, sizeof(nulls));
values[0] = Int64GetDatum(metadata->head);
values[1] = Int64GetDatum(metadata->tail);
values[2] = Int32GetDatum(metadata->tailFreeSize);
values[3] = Int64GetDatum(metadata->nPendingPages);
values[4] = Int64GetDatum(metadata->nPendingHeapTuples);
/* statistics, updated by VACUUM */
values[5] = Int64GetDatum(metadata->nTotalPages);
values[6] = Int64GetDatum(metadata->nEntryPages);
values[7] = Int64GetDatum(metadata->nDataPages);
values[8] = Int64GetDatum(metadata->nEntries);
values[9] = Int32GetDatum(metadata->ginVersion);
/* Build and return the result tuple. */
resultTuple = heap_form_tuple(tupdesc, values, nulls);
return HeapTupleGetDatum(resultTuple);
}
Datum
gin_page_opaque_info(PG_FUNCTION_ARGS)
{
bytea *raw_page = PG_GETARG_BYTEA_P(0);
int raw_page_size;
TupleDesc tupdesc;
Page page;
GinPageOpaque opaq;
HeapTuple resultTuple;
Datum values[3];
bool nulls[10];
Datum flags[16];
int nflags = 0;
uint16 flagbits;
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 (raw_page_size < BLCKSZ)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("input page too small (%d bytes)", raw_page_size)));
page = VARDATA(raw_page);
opaq = (GinPageOpaque) PageGetSpecialPointer(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");
/* Convert the flags bitmask to an array of human-readable names */
flagbits = opaq->flags;
if (flagbits & GIN_DATA)
flags[nflags++] = CStringGetTextDatum("data");
if (flagbits & GIN_LEAF)
flags[nflags++] = CStringGetTextDatum("leaf");
if (flagbits & GIN_DELETED)
flags[nflags++] = CStringGetTextDatum("deleted");
if (flagbits & GIN_META)
flags[nflags++] = CStringGetTextDatum("meta");
if (flagbits & GIN_LIST)
flags[nflags++] = CStringGetTextDatum("list");
if (flagbits & GIN_LIST_FULLROW)
flags[nflags++] = CStringGetTextDatum("list_fullrow");
if (flagbits & GIN_INCOMPLETE_SPLIT)
flags[nflags++] = CStringGetTextDatum("incomplete_split");
if (flagbits & GIN_COMPRESSED)
flags[nflags++] = CStringGetTextDatum("compressed");
flagbits &= ~(GIN_DATA | GIN_LEAF | GIN_DELETED | GIN_META | GIN_LIST |
GIN_LIST_FULLROW | GIN_INCOMPLETE_SPLIT | GIN_COMPRESSED);
if (flagbits)
{
/* any flags we don't recognize are printed in hex */
flags[nflags++] = DirectFunctionCall1(to_hex32, Int32GetDatum(flagbits));
}
memset(nulls, 0, sizeof(nulls));
values[0] = Int64GetDatum(opaq->rightlink);
values[1] = Int64GetDatum(opaq->maxoff);
values[2] = PointerGetDatum(
construct_array(flags, nflags, TEXTOID, -1, false, 'i'));
/* Build and return the result tuple. */
resultTuple = heap_form_tuple(tupdesc, values, nulls);
return HeapTupleGetDatum(resultTuple);
}
typedef struct gin_leafpage_items_state
{
TupleDesc tupd;
GinPostingList *seg;
GinPostingList *lastseg;
} gin_leafpage_items_state;
Datum
gin_leafpage_items(PG_FUNCTION_ARGS)
{
bytea *raw_page = PG_GETARG_BYTEA_P(0);
int raw_page_size;
FuncCallContext *fctx;
gin_leafpage_items_state *inter_call_data;
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;
Page page;
GinPageOpaque opaq;
if (raw_page_size < BLCKSZ)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("input page too small (%d bytes)", raw_page_size)));
page = VARDATA(raw_page);
if (PageGetSpecialSize(page) != MAXALIGN(sizeof(GinPageOpaqueData)))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("input page is not a valid GIN data leaf page"),
errdetail("Special size %d, expected %d",
(int) PageGetSpecialSize(page),
(int) MAXALIGN(sizeof(GinPageOpaqueData)))));
opaq = (GinPageOpaque) PageGetSpecialPointer(page);
if (opaq->flags != (GIN_DATA | GIN_LEAF | GIN_COMPRESSED))
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("input page is not a compressed GIN data leaf page"),
errdetail("Flags %04X, expected %04X",
opaq->flags,
(GIN_DATA | GIN_LEAF | GIN_COMPRESSED))));
fctx = SRF_FIRSTCALL_INIT();
mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
inter_call_data = palloc(sizeof(gin_leafpage_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->seg = GinDataLeafPageGetPostingList(page);
inter_call_data->lastseg = (GinPostingList *)
(((char *) inter_call_data->seg) +
GinDataLeafPageGetPostingListSize(page));
fctx->user_fctx = inter_call_data;
MemoryContextSwitchTo(mctx);
}
fctx = SRF_PERCALL_SETUP();
inter_call_data = fctx->user_fctx;
if (inter_call_data->seg != inter_call_data->lastseg)
{
GinPostingList *cur = inter_call_data->seg;
HeapTuple resultTuple;
Datum result;
Datum values[3];
bool nulls[3];
int ndecoded,
i;
ItemPointer tids;
Datum *tids_datum;
memset(nulls, 0, sizeof(nulls));
values[0] = ItemPointerGetDatum(&cur->first);
values[1] = UInt16GetDatum(cur->nbytes);
/* build an array of decoded item pointers */
tids = ginPostingListDecode(cur, &ndecoded);
tids_datum = (Datum *) palloc(ndecoded * sizeof(Datum));
for (i = 0; i < ndecoded; i++)
tids_datum[i] = ItemPointerGetDatum(&tids[i]);
values[2] = PointerGetDatum(construct_array(tids_datum,
ndecoded,
TIDOID,
sizeof(ItemPointerData),
false, 's'));
pfree(tids_datum);
pfree(tids);
/* Build and return the result tuple. */
resultTuple = heap_form_tuple(inter_call_data->tupd, values, nulls);
result = HeapTupleGetDatum(resultTuple);
inter_call_data->seg = GinNextPostingListSegment(cur);
SRF_RETURN_NEXT(fctx, result);
}
else
SRF_RETURN_DONE(fctx);
}

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@ -41,3 +41,41 @@ CREATE FUNCTION brin_page_items(IN page bytea, IN index_oid regclass,
RETURNS SETOF record
AS 'MODULE_PATHNAME', 'brin_page_items'
LANGUAGE C STRICT;
--
-- gin_metapage_info()
--
CREATE FUNCTION gin_metapage_info(IN page bytea,
OUT pending_head bigint,
OUT pending_tail bigint,
OUT tail_free_size int4,
OUT n_pending_pages bigint,
OUT n_pending_tuples bigint,
OUT n_total_pages bigint,
OUT n_entry_pages bigint,
OUT n_data_pages bigint,
OUT n_entries bigint,
OUT version int4)
AS 'MODULE_PATHNAME', 'gin_metapage_info'
LANGUAGE C STRICT;
--
-- gin_page_opaque_info()
--
CREATE FUNCTION gin_page_opaque_info(IN page bytea,
OUT rightlink bigint,
OUT maxoff int4,
OUT flags text[])
AS 'MODULE_PATHNAME', 'gin_page_opaque_info'
LANGUAGE C STRICT;
--
-- gin_leafpage_items()
--
CREATE FUNCTION gin_leafpage_items(IN page bytea,
OUT first_tid tid,
OUT nbytes int2,
OUT tids tid[])
RETURNS SETOF record
AS 'MODULE_PATHNAME', 'gin_leafpage_items'
LANGUAGE C STRICT;

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@ -144,3 +144,45 @@ CREATE FUNCTION fsm_page_contents(IN page bytea)
RETURNS text
AS 'MODULE_PATHNAME', 'fsm_page_contents'
LANGUAGE C STRICT;
--
-- GIN functions
--
--
-- gin_metapage_info()
--
CREATE FUNCTION gin_metapage_info(IN page bytea,
OUT pending_head bigint,
OUT pending_tail bigint,
OUT tail_free_size int4,
OUT n_pending_pages bigint,
OUT n_pending_tuples bigint,
OUT n_total_pages bigint,
OUT n_entry_pages bigint,
OUT n_data_pages bigint,
OUT n_entries bigint,
OUT version int4)
AS 'MODULE_PATHNAME', 'gin_metapage_info'
LANGUAGE C STRICT;
--
-- gin_page_opaque_info()
--
CREATE FUNCTION gin_page_opaque_info(IN page bytea,
OUT rightlink bigint,
OUT maxoff int4,
OUT flags text[])
AS 'MODULE_PATHNAME', 'gin_page_opaque_info'
LANGUAGE C STRICT;
--
-- gin_leafpage_items()
--
CREATE FUNCTION gin_leafpage_items(IN page bytea,
OUT first_tid tid,
OUT nbytes int2,
OUT tids tid[])
RETURNS SETOF record
AS 'MODULE_PATHNAME', 'gin_leafpage_items'
LANGUAGE C STRICT;

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@ -300,6 +300,91 @@ brintest-# order by blknum, attnum limit 6;
</listitem>
</varlistentry>
<varlistentry>
<term>
<function>gin_metapage_info(page bytea) returns record</function>
<indexterm>
<primary>gin_metapage_info</primary>
</indexterm>
</term>
<listitem>
<para>
<function>gin_metapage_info</function> returns information about
a <acronym>GIN</acronym> index metapage. For example:
<screen>
test=# SELECT * FROM gin_metapage_info(get_raw_page('gin_index', 0));
-[ RECORD 1 ]----+-----------
pending_head | 4294967295
pending_tail | 4294967295
tail_free_size | 0
n_pending_pages | 0
n_pending_tuples | 0
n_total_pages | 7
n_entry_pages | 6
n_data_pages | 0
n_entries | 693
version | 2
</screen>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<function>gin_page_opaque_info(page bytea) returns record</function>
<indexterm>
<primary>gin_page_opaque_info</primary>
</indexterm>
</term>
<listitem>
<para>
<function>gin_page_opaque_info</function> returns information about
a <acronym>GIN</acronym> index opaque area, like the page type.
For example:
<screen>
test=# SELECT * FROM gin_page_opaque_info(get_raw_page('gin_index', 2));
rightlink | maxoff | flags
-----------+--------+------------------------
5 | 0 | {data,leaf,compressed}
(1 row)
</screen>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<function>gin_leafpage_items(page bytea) returns setof record</function>
<indexterm>
<primary>gin_leafpage_items</primary>
</indexterm>
</term>
<listitem>
<para>
<function>gin_leafpage_items</function> returns information about
the data stored in a <acronym>GIN</acronym> leaf page. For example:
<screen>
test=# SELECT first_tid, nbytes, tids[0:5] as some_tids
FROM gin_leafpage_items(get_raw_page('gin_test_idx', 2));
first_tid | nbytes | some_tids
-----------+--------+----------------------------------------------------------
(8,41) | 244 | {"(8,41)","(8,43)","(8,44)","(8,45)","(8,46)"}
(10,45) | 248 | {"(10,45)","(10,46)","(10,47)","(10,48)","(10,49)"}
(12,52) | 248 | {"(12,52)","(12,53)","(12,54)","(12,55)","(12,56)"}
(14,59) | 320 | {"(14,59)","(14,60)","(14,61)","(14,62)","(14,63)"}
(167,16) | 376 | {"(167,16)","(167,17)","(167,18)","(167,19)","(167,20)"}
(170,30) | 376 | {"(170,30)","(170,31)","(170,32)","(170,33)","(170,34)"}
(173,44) | 197 | {"(173,44)","(173,45)","(173,46)","(173,47)","(173,48)"}
(7 rows)
</screen>
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<function>fsm_page_contents(page bytea) returns text</function>