On 09/21/2016 08:43 AM, Michael Paquier wrote:
page_stats / page_items should not be used on the metadata page.

As these functions are marked as superuser only it is expected that people
provides the correct input, especially since the raw page structure is used
as the input.

btree functions use the block number to do some sanity checks. You
cannot do that here as only bytea functions are available, but you
could do it in verify_hash_page by looking at the opaque data and look
at LH_META_PAGE. Then add a boolean argument into verify_hash_page to
see if the caller expects a meta page or not and just issue an error.
Actually it would be a good idea to put in those safeguards, even if I
agree with you that calling those functions is at the risk of the
user... Could you update the patch in this sense?

I had fun doing the same tests, aka running the items and stats
functions on a meta page, and the meta function on a non-meta page,
but at my surprise I did not see a crash, so perhaps I was lucky and
perhaps that was because of OSX.


Attached is v5, which add basic page verification.

Thanks for the feedback !

Best regards,
 Jesper

>From 05fe7b9056bcbb2f29809798229640499576c3a9 Mon Sep 17 00:00:00 2001
From: jesperpedersen <jesper.peder...@redhat.com>
Date: Fri, 5 Aug 2016 10:16:32 -0400
Subject: [PATCH] pageinspect: Hash index support

---
 contrib/pageinspect/Makefile                  |  10 +-
 contrib/pageinspect/hashfuncs.c               | 422 ++++++++++++++++++++++++++
 contrib/pageinspect/pageinspect--1.5--1.6.sql |  63 ++++
 contrib/pageinspect/pageinspect--1.5.sql      | 279 -----------------
 contrib/pageinspect/pageinspect--1.6.sql      | 338 +++++++++++++++++++++
 contrib/pageinspect/pageinspect.control       |   2 +-
 doc/src/sgml/pageinspect.sgml                 | 104 +++++++
 7 files changed, 933 insertions(+), 285 deletions(-)
 create mode 100644 contrib/pageinspect/hashfuncs.c
 create mode 100644 contrib/pageinspect/pageinspect--1.5--1.6.sql
 delete mode 100644 contrib/pageinspect/pageinspect--1.5.sql
 create mode 100644 contrib/pageinspect/pageinspect--1.6.sql

diff --git a/contrib/pageinspect/Makefile b/contrib/pageinspect/Makefile
index a98237e..c73d728 100644
--- a/contrib/pageinspect/Makefile
+++ b/contrib/pageinspect/Makefile
@@ -2,13 +2,13 @@
 
 MODULE_big	= pageinspect
 OBJS		= rawpage.o heapfuncs.o btreefuncs.o fsmfuncs.o \
-		  brinfuncs.o ginfuncs.o $(WIN32RES)
+		  brinfuncs.o ginfuncs.o hashfuncs.o $(WIN32RES)
 
 EXTENSION = pageinspect
-DATA = pageinspect--1.5.sql pageinspect--1.4--1.5.sql \
-	pageinspect--1.3--1.4.sql pageinspect--1.2--1.3.sql \
-	pageinspect--1.1--1.2.sql pageinspect--1.0--1.1.sql \
-	pageinspect--unpackaged--1.0.sql
+DATA = pageinspect--1.6.sql pageinspect--1.5--1.6.sql \
+	pageinspect--1.4--1.5.sql pageinspect--1.3--1.4.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
diff --git a/contrib/pageinspect/hashfuncs.c b/contrib/pageinspect/hashfuncs.c
new file mode 100644
index 0000000..3ee57dc
--- /dev/null
+++ b/contrib/pageinspect/hashfuncs.c
@@ -0,0 +1,422 @@
+/*
+ * hashfuncs.c
+ *		Functions to investigate the content of HASH indexes
+ *
+ * Copyright (c) 2016, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *		contrib/pageinspect/hashfuncs.c
+ */
+
+#include "postgres.h"
+
+#include "access/hash.h"
+#include "funcapi.h"
+#include "miscadmin.h"
+
+PG_FUNCTION_INFO_V1(hash_metap);
+PG_FUNCTION_INFO_V1(hash_page_items);
+PG_FUNCTION_INFO_V1(hash_page_stats);
+
+/* ------------------------------------------------
+ * structure for single hash page statistics
+ * ------------------------------------------------
+ */
+typedef struct HashPageStat
+{
+	uint32		live_items;
+	uint32		dead_items;
+	uint32		page_size;
+	uint32		max_avail;
+	uint32		free_size;
+	uint32		avg_item_size;
+	char		type;
+
+	/* opaque data */
+	BlockNumber hasho_prevblkno;
+	BlockNumber hasho_nextblkno;
+	Bucket		hasho_bucket;
+	uint16		hasho_flag;
+	uint16		hasho_page_id;
+} HashPageStat;
+
+
+/*
+ * Verify that the given bytea contains a HASH page, or die in the attempt.
+ * A pointer to the page is returned.
+ */
+static Page
+verify_hash_page(bytea *raw_page, bool metap)
+{
+	Page		page;
+	int			raw_page_size;
+	HashPageOpaque pageopaque;
+
+	raw_page_size = VARSIZE(raw_page) - VARHDRSZ;
+
+	if (raw_page_size != BLCKSZ)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("input page too small"),
+				 errdetail("Expected size %d, got %d",
+						   BLCKSZ, raw_page_size)));
+
+	page = VARDATA(raw_page);
+	pageopaque = (HashPageOpaque) PageGetSpecialPointer(page);
+	if (pageopaque->hasho_page_id != HASHO_PAGE_ID)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("page is not a HASH page"),
+				 errdetail("Expected %08x, got %08x.",
+						   HASHO_PAGE_ID, pageopaque->hasho_page_id)));
+
+	if (metap)
+	{
+		if (pageopaque->hasho_flag != LH_META_PAGE)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("page is not a metadata page"),
+					 errdetail("Expected %08x, got %08x.",
+							   LH_META_PAGE, pageopaque->hasho_flag)));
+	}
+	else
+	{
+		if (pageopaque->hasho_flag == LH_META_PAGE)
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("page is a metadata page"),
+					 errdetail("Flags %08x.",
+							   pageopaque->hasho_flag)));
+	}
+
+	return page;
+}
+
+/* -------------------------------------------------
+ * GetHashPageStatistics()
+ *
+ * Collect statistics of single hash page
+ * -------------------------------------------------
+ */
+static void
+GetHashPageStatistics(Page page, HashPageStat *stat)
+{
+	PageHeader	phdr = (PageHeader) page;
+	OffsetNumber maxoff = PageGetMaxOffsetNumber(page);
+	HashPageOpaque opaque = (HashPageOpaque) PageGetSpecialPointer(page);
+	int			item_size = 0;
+	int			off;
+
+	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 (opaque->hasho_flag & LH_META_PAGE)
+		stat->type = 'm';
+	else if (opaque->hasho_flag & LH_OVERFLOW_PAGE)
+		stat->type = 'v';
+	else if (opaque->hasho_flag & LH_BUCKET_PAGE)
+		stat->type = 'b';
+	else if (opaque->hasho_flag & LH_BITMAP_PAGE)
+		stat->type = 'i';
+	else
+		stat->type = 'u';
+
+	/* hash page opaque data */
+	stat->hasho_prevblkno = opaque->hasho_prevblkno;
+	stat->hasho_nextblkno = opaque->hasho_nextblkno;
+	stat->hasho_bucket = opaque->hasho_bucket;
+	stat->hasho_flag = opaque->hasho_flag;
+	stat->hasho_page_id = opaque->hasho_page_id;
+
+	/* 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 (!ItemIdIsDead(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;
+}
+
+/* ---------------------------------------------------
+ * hash_page_stats()
+ *
+ * Usage: SELECT * FROM hash_page_stats(get_raw_page('t1_hash', 1));
+ * ---------------------------------------------------
+ */
+Datum
+hash_page_stats(PG_FUNCTION_ARGS)
+{
+	bytea	   *raw_page = PG_GETARG_BYTEA_P(0);
+	Page		page;
+	int			j;
+	char	   *values[11];
+	HashPageStat	stat;
+	Datum		result;
+	HeapTuple	tuple;
+	TupleDesc	tupleDesc;
+
+	if (!superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to use pageinspect functions"))));
+
+	page = verify_hash_page(raw_page, false);
+
+	/* keep compiler quiet */
+	stat.hasho_prevblkno = stat.hasho_nextblkno = InvalidBlockNumber;
+	stat.hasho_flag = stat.hasho_page_id = stat.free_size = stat.avg_item_size = 0;
+
+	GetHashPageStatistics(page, &stat);
+
+	/* Build a tuple descriptor for our result type */
+	if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
+		elog(ERROR, "return type must be a row type");
+	tupleDesc = BlessTupleDesc(tupleDesc);
+
+	j = 0;
+	values[j++] = psprintf("%c", stat.type);
+	values[j++] = psprintf("%d", stat.live_items);
+	values[j++] = psprintf("%d", stat.dead_items);
+	values[j++] = psprintf("%d", stat.avg_item_size);
+	values[j++] = psprintf("%d", stat.page_size);
+	values[j++] = psprintf("%d", stat.free_size);
+	values[j++] = psprintf("%d", stat.hasho_prevblkno);
+	values[j++] = psprintf("%d", stat.hasho_nextblkno);
+	values[j++] = psprintf("%d", stat.hasho_bucket);
+	values[j++] = psprintf("%d", stat.hasho_flag);
+	values[j++] = psprintf("%d", stat.hasho_page_id);
+
+	tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(tupleDesc),
+								   values);
+
+	result = HeapTupleGetDatum(tuple);
+
+	PG_RETURN_DATUM(result);
+}
+
+/*
+ * cross-call data structure for SRF
+ */
+struct user_args
+{
+	Page		page;
+	OffsetNumber offset;
+};
+
+/*-------------------------------------------------------
+ * hash_page_items()
+ *
+ * Get IndexTupleData set in a hash page
+ *
+ * Usage: SELECT * FROM hash_page_items(get_raw_page('t1_hash', 1));
+ *-------------------------------------------------------
+ */
+Datum
+hash_page_items(PG_FUNCTION_ARGS)
+{
+	bytea	   *raw_page = PG_GETARG_BYTEA_P(0);
+	Page		page;
+	Datum		result;
+	char	   *values[6];
+	HeapTuple	tuple;
+	FuncCallContext *fctx;
+	MemoryContext mctx;
+	struct user_args *uargs;
+
+	if (!superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to use pageinspect functions"))));
+
+	if (SRF_IS_FIRSTCALL())
+	{
+		TupleDesc	tupleDesc;
+
+		fctx = SRF_FIRSTCALL_INIT();
+
+		page = verify_hash_page(raw_page, false);
+
+		/*
+		 * We copy the page into local storage to avoid holding pin on the
+		 * buffer longer than we must, and possibly failing to release it at
+		 * all if the calling query doesn't fetch all rows.
+		 */
+		mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
+
+		uargs = palloc(sizeof(struct user_args));
+
+		uargs->page = palloc(BLCKSZ);
+		memcpy(uargs->page, page, BLCKSZ);
+
+		uargs->offset = FirstOffsetNumber;
+
+		fctx->max_calls = PageGetMaxOffsetNumber(uargs->page);
+
+		/* Build a tuple descriptor for our result type */
+		if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
+			elog(ERROR, "return type must be a row type");
+		tupleDesc = BlessTupleDesc(tupleDesc);
+
+		fctx->attinmeta = TupleDescGetAttInMetadata(tupleDesc);
+
+		fctx->user_fctx = uargs;
+
+		MemoryContextSwitchTo(mctx);
+	}
+
+	fctx = SRF_PERCALL_SETUP();
+	uargs = fctx->user_fctx;
+
+	if (fctx->call_cntr < fctx->max_calls)
+	{
+		ItemId		id;
+		IndexTuple	itup;
+		int			j;
+		int			off;
+		int			dlen;
+		char	   *dump;
+		char	   *ptr;
+
+		id = PageGetItemId(uargs->page, uargs->offset);
+
+		if (!ItemIdIsValid(id))
+			elog(ERROR, "invalid ItemId");
+
+		itup = (IndexTuple) PageGetItem(uargs->page, id);
+
+		j = 0;
+		values[j++] = psprintf("%d", uargs->offset);
+		values[j++] = psprintf("(%u,%u)",
+							   BlockIdGetBlockNumber(&(itup->t_tid.ip_blkid)),
+							   itup->t_tid.ip_posid);
+		values[j++] = psprintf("%d", (int) IndexTupleSize(itup));
+		values[j++] = psprintf("%c", IndexTupleHasNulls(itup) ? 't' : 'f');
+		values[j++] = psprintf("%c", IndexTupleHasVarwidths(itup) ? 't' : 'f');
+
+		ptr = (char *) itup + IndexInfoFindDataOffset(itup->t_info);
+		dlen = IndexTupleSize(itup) - IndexInfoFindDataOffset(itup->t_info);
+		dump = palloc0(dlen * 3 + 1);
+		values[j] = dump;
+		for (off = 0; off < dlen; off++)
+		{
+			if (off > 0)
+				*dump++ = ' ';
+			sprintf(dump, "%02x", *(ptr + off) & 0xff);
+			dump += 2;
+		}
+
+		tuple = BuildTupleFromCStrings(fctx->attinmeta, values);
+		result = HeapTupleGetDatum(tuple);
+
+		uargs->offset = uargs->offset + 1;
+
+		SRF_RETURN_NEXT(fctx, result);
+	}
+	else
+	{
+		pfree(uargs->page);
+		pfree(uargs);
+		SRF_RETURN_DONE(fctx);
+	}
+}
+
+/* ------------------------------------------------
+ * hash_metap()
+ *
+ * Get a hash's meta-page information
+ *
+ * Usage: SELECT * FROM hash_metap(get_raw_page('t1_hash', 0))
+ * ------------------------------------------------
+ */
+Datum
+hash_metap(PG_FUNCTION_ARGS)
+{
+	bytea	   *raw_page = PG_GETARG_BYTEA_P(0);
+	Datum	    result;
+	Page		page;
+	HashMetaPageData *metad;
+	TupleDesc	tupleDesc;
+	HeapTuple	tuple;
+	int			i,j;
+	char	   *values[16];
+	char       *spares;
+	char       *mapp;
+
+	if (!superuser())
+		ereport(ERROR,
+				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+				 (errmsg("must be superuser to use pageinspect functions"))));
+
+	page = verify_hash_page(raw_page, true);
+
+	/* Build a tuple descriptor for our result type */
+	if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
+		elog(ERROR, "return type must be a row type");
+	tupleDesc = BlessTupleDesc(tupleDesc);
+
+	metad = HashPageGetMeta(page);
+
+	j = 0;
+	values[j++] = psprintf("%d", metad->hashm_magic);
+	values[j++] = psprintf("%d", metad->hashm_version);
+	values[j++] = psprintf("%f", metad->hashm_ntuples);
+	values[j++] = psprintf("%d", metad->hashm_ffactor);
+	values[j++] = psprintf("%d", metad->hashm_bsize);
+	values[j++] = psprintf("%d", metad->hashm_bmsize);
+	values[j++] = psprintf("%d", metad->hashm_bmshift);
+	values[j++] = psprintf("%d", metad->hashm_maxbucket);
+	values[j++] = psprintf("%d", metad->hashm_highmask);
+	values[j++] = psprintf("%d", metad->hashm_lowmask);
+	values[j++] = psprintf("%d", metad->hashm_ovflpoint);
+	values[j++] = psprintf("%d", metad->hashm_firstfree);
+	values[j++] = psprintf("%d", metad->hashm_nmaps);
+	values[j++] = psprintf("%d", metad->hashm_procid);
+
+	spares = palloc0(HASH_MAX_SPLITPOINTS * 5 + 1);
+	values[j++] = spares;
+	for (i = 0; i < HASH_MAX_SPLITPOINTS; i++)
+	{
+		if (i > 0)
+			*spares++ = ' ';
+
+		sprintf(spares, "%04x", metad->hashm_spares[i]);
+		spares += 4;
+	}
+
+	mapp = palloc0(HASH_MAX_BITMAPS * 5 + 1);
+	values[j++] = mapp;
+	for (i = 0; i < HASH_MAX_BITMAPS; i++)
+	{
+		if (i > 0)
+			*mapp++ = ' ';
+
+		sprintf(mapp, "%04x", metad->hashm_mapp[i]);
+		mapp += 4;
+	}
+
+	tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(tupleDesc),
+								   values);
+
+	result = HeapTupleGetDatum(tuple);
+
+	PG_RETURN_DATUM(result);
+}
diff --git a/contrib/pageinspect/pageinspect--1.5--1.6.sql b/contrib/pageinspect/pageinspect--1.5--1.6.sql
new file mode 100644
index 0000000..a60df65
--- /dev/null
+++ b/contrib/pageinspect/pageinspect--1.5--1.6.sql
@@ -0,0 +1,63 @@
+/* contrib/pageinspect/pageinspect--1.5--1.6.sql */
+
+-- complain if script is sourced in psql, rather than via ALTER EXTENSION
+\echo Use "ALTER EXTENSION pageinspect UPDATE TO '1.6'" to load this file. \quit
+
+--
+-- HASH functions
+--
+
+--
+-- hash_metap()
+--
+CREATE FUNCTION hash_metap(IN page bytea,
+    OUT magic int4,
+    OUT version int4,
+    OUT ntuples double precision,
+    OUT ffactor int2,
+    OUT bsize int2,
+    OUT bmsize int2,
+    OUT bmshift int2,
+    OUT maxbucket int4,
+    OUT highmask int4,
+    OUT lowmask int4,
+    OUT ovflpoint int4,
+    OUT firstfree int4,
+    OUT nmaps int4,
+    OUT procid int4,
+    OUT spares text,
+    OUT mapp text)
+AS 'MODULE_PATHNAME', 'hash_metap'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+--
+-- hash_page_stats()
+--
+CREATE FUNCTION hash_page_stats(IN page bytea,
+    OUT type "char",
+    OUT live_items int4,
+    OUT dead_items int4,
+    OUT avg_item_size int4,
+    OUT page_size int4,
+    OUT free_size int4,
+    OUT hasho_prevblkno int4,
+    OUT hasho_nextblkno int4,
+    OUT hasho_bucket int4,
+    OUT hasho_flag int4,
+    OUT hasho_page_id int4)
+AS 'MODULE_PATHNAME', 'hash_page_stats'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+--
+-- hash_page_items()
+--
+CREATE FUNCTION hash_page_items(IN page bytea,
+    OUT itemoffset smallint,
+    OUT ctid tid,
+    OUT itemlen smallint,
+    OUT nulls bool,
+    OUT vars bool,
+    OUT data text)
+RETURNS SETOF record
+AS 'MODULE_PATHNAME', 'hash_page_items'
+LANGUAGE C STRICT PARALLEL SAFE;
diff --git a/contrib/pageinspect/pageinspect--1.5.sql b/contrib/pageinspect/pageinspect--1.5.sql
deleted file mode 100644
index 1e40c3c..0000000
--- a/contrib/pageinspect/pageinspect--1.5.sql
+++ /dev/null
@@ -1,279 +0,0 @@
-/* contrib/pageinspect/pageinspect--1.5.sql */
-
--- complain if script is sourced in psql, rather than via CREATE EXTENSION
-\echo Use "CREATE EXTENSION pageinspect" to load this file. \quit
-
---
--- get_raw_page()
---
-CREATE FUNCTION get_raw_page(text, int4)
-RETURNS bytea
-AS 'MODULE_PATHNAME', 'get_raw_page'
-LANGUAGE C STRICT PARALLEL SAFE;
-
-CREATE FUNCTION get_raw_page(text, text, int4)
-RETURNS bytea
-AS 'MODULE_PATHNAME', 'get_raw_page_fork'
-LANGUAGE C STRICT PARALLEL SAFE;
-
---
--- page_header()
---
-CREATE FUNCTION page_header(IN page bytea,
-    OUT lsn pg_lsn,
-    OUT checksum smallint,
-    OUT flags smallint,
-    OUT lower smallint,
-    OUT upper smallint,
-    OUT special smallint,
-    OUT pagesize smallint,
-    OUT version smallint,
-    OUT prune_xid xid)
-AS 'MODULE_PATHNAME', 'page_header'
-LANGUAGE C STRICT PARALLEL SAFE;
-
---
--- heap_page_items()
---
-CREATE FUNCTION heap_page_items(IN page bytea,
-    OUT lp smallint,
-    OUT lp_off smallint,
-    OUT lp_flags smallint,
-    OUT lp_len smallint,
-    OUT t_xmin xid,
-    OUT t_xmax xid,
-    OUT t_field3 int4,
-    OUT t_ctid tid,
-    OUT t_infomask2 integer,
-    OUT t_infomask integer,
-    OUT t_hoff smallint,
-    OUT t_bits text,
-    OUT t_oid oid,
-    OUT t_data bytea)
-RETURNS SETOF record
-AS 'MODULE_PATHNAME', 'heap_page_items'
-LANGUAGE C STRICT PARALLEL SAFE;
-
---
--- tuple_data_split()
---
-CREATE FUNCTION tuple_data_split(rel_oid oid,
-    t_data bytea,
-    t_infomask integer,
-    t_infomask2 integer,
-    t_bits text)
-RETURNS bytea[]
-AS 'MODULE_PATHNAME','tuple_data_split'
-LANGUAGE C PARALLEL SAFE;
-
-CREATE FUNCTION tuple_data_split(rel_oid oid,
-    t_data bytea,
-    t_infomask integer,
-    t_infomask2 integer,
-    t_bits text,
-    do_detoast bool)
-RETURNS bytea[]
-AS 'MODULE_PATHNAME','tuple_data_split'
-LANGUAGE C PARALLEL SAFE;
-
---
--- heap_page_item_attrs()
---
-CREATE FUNCTION heap_page_item_attrs(
-    IN page bytea,
-    IN rel_oid regclass,
-    IN do_detoast bool,
-    OUT lp smallint,
-    OUT lp_off smallint,
-    OUT lp_flags smallint,
-    OUT lp_len smallint,
-    OUT t_xmin xid,
-    OUT t_xmax xid,
-    OUT t_field3 int4,
-    OUT t_ctid tid,
-    OUT t_infomask2 integer,
-    OUT t_infomask integer,
-    OUT t_hoff smallint,
-    OUT t_bits text,
-    OUT t_oid oid,
-    OUT t_attrs bytea[]
-    )
-RETURNS SETOF record AS $$
-SELECT lp,
-       lp_off,
-       lp_flags,
-       lp_len,
-       t_xmin,
-       t_xmax,
-       t_field3,
-       t_ctid,
-       t_infomask2,
-       t_infomask,
-       t_hoff,
-       t_bits,
-       t_oid,
-       tuple_data_split(
-         rel_oid,
-         t_data,
-         t_infomask,
-         t_infomask2,
-         t_bits,
-         do_detoast)
-         AS t_attrs
-  FROM heap_page_items(page);
-$$ LANGUAGE SQL PARALLEL SAFE;
-
-CREATE FUNCTION heap_page_item_attrs(IN page bytea, IN rel_oid regclass,
-    OUT lp smallint,
-    OUT lp_off smallint,
-    OUT lp_flags smallint,
-    OUT lp_len smallint,
-    OUT t_xmin xid,
-    OUT t_xmax xid,
-    OUT t_field3 int4,
-    OUT t_ctid tid,
-    OUT t_infomask2 integer,
-    OUT t_infomask integer,
-    OUT t_hoff smallint,
-    OUT t_bits text,
-    OUT t_oid oid,
-    OUT t_attrs bytea[]
-    )
-RETURNS SETOF record AS $$
-SELECT * from heap_page_item_attrs(page, rel_oid, false);
-$$ LANGUAGE SQL PARALLEL SAFE;
-
---
--- bt_metap()
---
-CREATE FUNCTION bt_metap(IN relname text,
-    OUT magic int4,
-    OUT version int4,
-    OUT root int4,
-    OUT level int4,
-    OUT fastroot int4,
-    OUT fastlevel int4)
-AS 'MODULE_PATHNAME', 'bt_metap'
-LANGUAGE C STRICT PARALLEL SAFE;
-
---
--- bt_page_stats()
---
-CREATE FUNCTION bt_page_stats(IN relname text, IN blkno int4,
-    OUT blkno int4,
-    OUT type "char",
-    OUT live_items int4,
-    OUT dead_items int4,
-    OUT avg_item_size int4,
-    OUT page_size int4,
-    OUT free_size int4,
-    OUT btpo_prev int4,
-    OUT btpo_next int4,
-    OUT btpo int4,
-    OUT btpo_flags int4)
-AS 'MODULE_PATHNAME', 'bt_page_stats'
-LANGUAGE C STRICT PARALLEL SAFE;
-
---
--- bt_page_items()
---
-CREATE FUNCTION bt_page_items(IN relname text, IN blkno int4,
-    OUT itemoffset smallint,
-    OUT ctid tid,
-    OUT itemlen smallint,
-    OUT nulls bool,
-    OUT vars bool,
-    OUT data text)
-RETURNS SETOF record
-AS 'MODULE_PATHNAME', 'bt_page_items'
-LANGUAGE C STRICT PARALLEL SAFE;
-
---
--- brin_page_type()
---
-CREATE FUNCTION brin_page_type(IN page bytea)
-RETURNS text
-AS 'MODULE_PATHNAME', 'brin_page_type'
-LANGUAGE C STRICT PARALLEL SAFE;
-
---
--- brin_metapage_info()
---
-CREATE FUNCTION brin_metapage_info(IN page bytea, OUT magic text,
-	OUT version integer, OUT pagesperrange integer, OUT lastrevmappage bigint)
-AS 'MODULE_PATHNAME', 'brin_metapage_info'
-LANGUAGE C STRICT PARALLEL SAFE;
-
---
--- brin_revmap_data()
---
-CREATE FUNCTION brin_revmap_data(IN page bytea,
-	OUT pages tid)
-RETURNS SETOF tid
-AS 'MODULE_PATHNAME', 'brin_revmap_data'
-LANGUAGE C STRICT PARALLEL SAFE;
-
---
--- brin_page_items()
---
-CREATE FUNCTION brin_page_items(IN page bytea, IN index_oid regclass,
-	OUT itemoffset int,
-	OUT blknum int,
-	OUT attnum int,
-	OUT allnulls bool,
-	OUT hasnulls bool,
-	OUT placeholder bool,
-	OUT value text)
-RETURNS SETOF record
-AS 'MODULE_PATHNAME', 'brin_page_items'
-LANGUAGE C STRICT PARALLEL SAFE;
-
---
--- fsm_page_contents()
---
-CREATE FUNCTION fsm_page_contents(IN page bytea)
-RETURNS text
-AS 'MODULE_PATHNAME', 'fsm_page_contents'
-LANGUAGE C STRICT PARALLEL SAFE;
-
---
--- 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 PARALLEL SAFE;
-
---
--- 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 PARALLEL SAFE;
-
---
--- 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 PARALLEL SAFE;
diff --git a/contrib/pageinspect/pageinspect--1.6.sql b/contrib/pageinspect/pageinspect--1.6.sql
new file mode 100644
index 0000000..65e07a9
--- /dev/null
+++ b/contrib/pageinspect/pageinspect--1.6.sql
@@ -0,0 +1,338 @@
+/* contrib/pageinspect/pageinspect--1.6.sql */
+
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION pageinspect" to load this file. \quit
+
+--
+-- get_raw_page()
+--
+CREATE FUNCTION get_raw_page(text, int4)
+RETURNS bytea
+AS 'MODULE_PATHNAME', 'get_raw_page'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+CREATE FUNCTION get_raw_page(text, text, int4)
+RETURNS bytea
+AS 'MODULE_PATHNAME', 'get_raw_page_fork'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+--
+-- page_header()
+--
+CREATE FUNCTION page_header(IN page bytea,
+    OUT lsn pg_lsn,
+    OUT checksum smallint,
+    OUT flags smallint,
+    OUT lower smallint,
+    OUT upper smallint,
+    OUT special smallint,
+    OUT pagesize smallint,
+    OUT version smallint,
+    OUT prune_xid xid)
+AS 'MODULE_PATHNAME', 'page_header'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+--
+-- heap_page_items()
+--
+CREATE FUNCTION heap_page_items(IN page bytea,
+    OUT lp smallint,
+    OUT lp_off smallint,
+    OUT lp_flags smallint,
+    OUT lp_len smallint,
+    OUT t_xmin xid,
+    OUT t_xmax xid,
+    OUT t_field3 int4,
+    OUT t_ctid tid,
+    OUT t_infomask2 integer,
+    OUT t_infomask integer,
+    OUT t_hoff smallint,
+    OUT t_bits text,
+    OUT t_oid oid,
+    OUT t_data bytea)
+RETURNS SETOF record
+AS 'MODULE_PATHNAME', 'heap_page_items'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+--
+-- tuple_data_split()
+--
+CREATE FUNCTION tuple_data_split(rel_oid oid,
+    t_data bytea,
+    t_infomask integer,
+    t_infomask2 integer,
+    t_bits text)
+RETURNS bytea[]
+AS 'MODULE_PATHNAME','tuple_data_split'
+LANGUAGE C PARALLEL SAFE;
+
+CREATE FUNCTION tuple_data_split(rel_oid oid,
+    t_data bytea,
+    t_infomask integer,
+    t_infomask2 integer,
+    t_bits text,
+    do_detoast bool)
+RETURNS bytea[]
+AS 'MODULE_PATHNAME','tuple_data_split'
+LANGUAGE C PARALLEL SAFE;
+
+--
+-- heap_page_item_attrs()
+--
+CREATE FUNCTION heap_page_item_attrs(
+    IN page bytea,
+    IN rel_oid regclass,
+    IN do_detoast bool,
+    OUT lp smallint,
+    OUT lp_off smallint,
+    OUT lp_flags smallint,
+    OUT lp_len smallint,
+    OUT t_xmin xid,
+    OUT t_xmax xid,
+    OUT t_field3 int4,
+    OUT t_ctid tid,
+    OUT t_infomask2 integer,
+    OUT t_infomask integer,
+    OUT t_hoff smallint,
+    OUT t_bits text,
+    OUT t_oid oid,
+    OUT t_attrs bytea[]
+    )
+RETURNS SETOF record AS $$
+SELECT lp,
+       lp_off,
+       lp_flags,
+       lp_len,
+       t_xmin,
+       t_xmax,
+       t_field3,
+       t_ctid,
+       t_infomask2,
+       t_infomask,
+       t_hoff,
+       t_bits,
+       t_oid,
+       tuple_data_split(
+         rel_oid,
+         t_data,
+         t_infomask,
+         t_infomask2,
+         t_bits,
+         do_detoast)
+         AS t_attrs
+  FROM heap_page_items(page);
+$$ LANGUAGE SQL PARALLEL SAFE;
+
+CREATE FUNCTION heap_page_item_attrs(IN page bytea, IN rel_oid regclass,
+    OUT lp smallint,
+    OUT lp_off smallint,
+    OUT lp_flags smallint,
+    OUT lp_len smallint,
+    OUT t_xmin xid,
+    OUT t_xmax xid,
+    OUT t_field3 int4,
+    OUT t_ctid tid,
+    OUT t_infomask2 integer,
+    OUT t_infomask integer,
+    OUT t_hoff smallint,
+    OUT t_bits text,
+    OUT t_oid oid,
+    OUT t_attrs bytea[]
+    )
+RETURNS SETOF record AS $$
+SELECT * from heap_page_item_attrs(page, rel_oid, false);
+$$ LANGUAGE SQL PARALLEL SAFE;
+
+--
+-- bt_metap()
+--
+CREATE FUNCTION bt_metap(IN relname text,
+    OUT magic int4,
+    OUT version int4,
+    OUT root int4,
+    OUT level int4,
+    OUT fastroot int4,
+    OUT fastlevel int4)
+AS 'MODULE_PATHNAME', 'bt_metap'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+--
+-- bt_page_stats()
+--
+CREATE FUNCTION bt_page_stats(IN relname text, IN blkno int4,
+    OUT blkno int4,
+    OUT type "char",
+    OUT live_items int4,
+    OUT dead_items int4,
+    OUT avg_item_size int4,
+    OUT page_size int4,
+    OUT free_size int4,
+    OUT btpo_prev int4,
+    OUT btpo_next int4,
+    OUT btpo int4,
+    OUT btpo_flags int4)
+AS 'MODULE_PATHNAME', 'bt_page_stats'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+--
+-- bt_page_items()
+--
+CREATE FUNCTION bt_page_items(IN relname text, IN blkno int4,
+    OUT itemoffset smallint,
+    OUT ctid tid,
+    OUT itemlen smallint,
+    OUT nulls bool,
+    OUT vars bool,
+    OUT data text)
+RETURNS SETOF record
+AS 'MODULE_PATHNAME', 'bt_page_items'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+--
+-- brin_page_type()
+--
+CREATE FUNCTION brin_page_type(IN page bytea)
+RETURNS text
+AS 'MODULE_PATHNAME', 'brin_page_type'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+--
+-- brin_metapage_info()
+--
+CREATE FUNCTION brin_metapage_info(IN page bytea, OUT magic text,
+	OUT version integer, OUT pagesperrange integer, OUT lastrevmappage bigint)
+AS 'MODULE_PATHNAME', 'brin_metapage_info'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+--
+-- brin_revmap_data()
+--
+CREATE FUNCTION brin_revmap_data(IN page bytea,
+	OUT pages tid)
+RETURNS SETOF tid
+AS 'MODULE_PATHNAME', 'brin_revmap_data'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+--
+-- brin_page_items()
+--
+CREATE FUNCTION brin_page_items(IN page bytea, IN index_oid regclass,
+	OUT itemoffset int,
+	OUT blknum int,
+	OUT attnum int,
+	OUT allnulls bool,
+	OUT hasnulls bool,
+	OUT placeholder bool,
+	OUT value text)
+RETURNS SETOF record
+AS 'MODULE_PATHNAME', 'brin_page_items'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+--
+-- fsm_page_contents()
+--
+CREATE FUNCTION fsm_page_contents(IN page bytea)
+RETURNS text
+AS 'MODULE_PATHNAME', 'fsm_page_contents'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+--
+-- 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 PARALLEL SAFE;
+
+--
+-- 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 PARALLEL SAFE;
+
+--
+-- 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 PARALLEL SAFE;
+
+--
+-- HASH functions
+--
+
+--
+-- hash_metap()
+--
+CREATE FUNCTION hash_metap(IN page bytea,
+    OUT magic int4,
+    OUT version int4,
+    OUT ntuples double precision,
+    OUT ffactor int2,
+    OUT bsize int2,
+    OUT bmsize int2,
+    OUT bmshift int2,
+    OUT maxbucket int4,
+    OUT highmask int4,
+    OUT lowmask int4,
+    OUT ovflpoint int4,
+    OUT firstfree int4,
+    OUT nmaps int4,
+    OUT procid int4,
+    OUT spares text,
+    OUT mapp text)
+AS 'MODULE_PATHNAME', 'hash_metap'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+--
+-- hash_page_stats()
+--
+CREATE FUNCTION hash_page_stats(IN page bytea,
+    OUT type "char",
+    OUT live_items int4,
+    OUT dead_items int4,
+    OUT avg_item_size int4,
+    OUT page_size int4,
+    OUT free_size int4,
+    OUT hasho_prevblkno int4,
+    OUT hasho_nextblkno int4,
+    OUT hasho_bucket int4,
+    OUT hasho_flag int4,
+    OUT hasho_page_id int4)
+AS 'MODULE_PATHNAME', 'hash_page_stats'
+LANGUAGE C STRICT PARALLEL SAFE;
+
+--
+-- hash_page_items()
+--
+CREATE FUNCTION hash_page_items(IN page bytea,
+    OUT itemoffset smallint,
+    OUT ctid tid,
+    OUT itemlen smallint,
+    OUT nulls bool,
+    OUT vars bool,
+    OUT data text)
+RETURNS SETOF record
+AS 'MODULE_PATHNAME', 'hash_page_items'
+LANGUAGE C STRICT PARALLEL SAFE;
diff --git a/contrib/pageinspect/pageinspect.control b/contrib/pageinspect/pageinspect.control
index 23c8eff..1a61c9f 100644
--- a/contrib/pageinspect/pageinspect.control
+++ b/contrib/pageinspect/pageinspect.control
@@ -1,5 +1,5 @@
 # pageinspect extension
 comment = 'inspect the contents of database pages at a low level'
-default_version = '1.5'
+default_version = '1.6'
 module_pathname = '$libdir/pageinspect'
 relocatable = true
diff --git a/doc/src/sgml/pageinspect.sgml b/doc/src/sgml/pageinspect.sgml
index 5d187ed..8923842 100644
--- a/doc/src/sgml/pageinspect.sgml
+++ b/doc/src/sgml/pageinspect.sgml
@@ -452,6 +452,110 @@ test=# SELECT first_tid, nbytes, tids[0:5] as some_tids
 
    <varlistentry>
     <term>
+     <function>hash_metap(page bytes) returns record</function>
+     <indexterm>
+      <primary>hash_metap</primary>
+     </indexterm>
+    </term>
+
+    <listitem>
+     <para>
+      <function>hash_metap</function> returns information about a hash
+      index's metapage.  For example:
+<screen>
+test=# SELECT * FROM hash_metap(get_raw_page('mytab_index', 0));
+-[ RECORD 1 ]-----
+magic     | 105121344
+version   | 2
+ntuples   | 1000000
+ffactor   | 307
+bsize     | 8152
+bmsize    | 4096
+bmshift   | 15
+maxbucket | 4095
+highmask  | 8191
+lowmask   | 4095
+ovflpoint | 12
+firstfree | 0
+nmaps     | 1
+procid    | 400
+spares    | 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0001 0000 ...
+mapp      | 1001 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 ...
+</screen>
+     </para>
+    </listitem>
+   </varlistentry>
+
+   <varlistentry>
+    <term>
+     <function>hash_page_stats(page bytea, blkno int) returns record</function>
+     <indexterm>
+      <primary>hash_page_stats</primary>
+     </indexterm>
+    </term>
+
+    <listitem>
+     <para>
+      <function>hash_page_stats</function> returns summary information about
+      single pages of hash indexes.  For example:
+<screen>
+test=# SELECT * FROM hash_page_stats(get_raw_page('mytab_index', 1));
+-[ RECORD 1 ]-+-----
+type            | b
+live_items      | 211
+dead_items      | 0
+avg_item_size   | 16
+page_size       | 8192
+free_size       | 3928
+hasho_prevblkno | -1
+hasho_nextblkno | -1
+hasho_bucket    | 0
+hasho_flag      | 2
+hasho_page_id   | 65408
+</screen>
+     </para>
+     <para>
+      The type information will be '<literal>m</literal>' for a metadata page,
+      '<literal>v</literal>' for an overflow page, '<literal>b</literal>' for a bucket page,
+      '<literal>i</literal>' for a bitmap page, and '<literal>u</literal>' for an unused page.
+     </para>
+    </listitem>
+   </varlistentry>
+
+   <varlistentry>
+    <term>
+     <function>hash_page_items(page bytea) returns setof record</function>
+     <indexterm>
+      <primary>hash_page_items</primary>
+     </indexterm>
+    </term>
+
+    <listitem>
+     <para>
+      <function>hash_page_items</function> returns detailed information about
+      all of the items on a hash index page.  For example:
+<screen>
+test=# SELECT * FROM hash_page_items(get_raw_page('mytab_index', 1));     
+ itemoffset |    ctid    | itemlen | nulls | vars |          data           
+------------+------------+---------+-------+------+-------------------------
+          1 | (2057,114) |      16 | f     | f    | 00 a0 25 02 00 00 00 00
+          2 | (4033,38)  |      16 | f     | f    | 00 20 8d 02 00 00 00 00
+          3 | (4223,130) |      16 | f     | f    | 00 80 f7 02 00 00 00 00
+          4 | (1524,126) |      16 | f     | f    | 00 70 de 04 00 00 00 00
+          5 | (5850,86)  |      16 | f     | f    | 00 70 1a 07 00 00 00 00
+...
+        210 | (5541,140) |      16 | f     | f    | 00 90 a9 ff 00 00 00 00
+        211 | (4654,93)  |      16 | f     | f    | 00 d0 fb ff 00 00 00 00
+
+</screen>
+      The <structfield>ctid</> column points to a heap tuple 
+      (BlockIdData,OffsetNumber).
+     </para>
+    </listitem>
+   </varlistentry>
+
+   <varlistentry>
+    <term>
      <function>fsm_page_contents(page bytea) returns text</function>
      <indexterm>
       <primary>fsm_page_contents</primary>
-- 
2.7.4

-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers

Reply via email to