From 03482265b539bfd46ce684935c4b6697217dfe21 Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Tue, 1 Mar 2016 20:55:43 -0500 Subject: [PATCH 2/2] pg_visibilitymap --- contrib/pg_visibilitymap/Makefile | 19 ++++++ contrib/pg_visibilitymap/pg_visibilitymap--1.0.sql | 46 ++++++++++++++ contrib/pg_visibilitymap/pg_visibilitymap.c | 70 ++++++++++++++++++++++ contrib/pg_visibilitymap/pg_visibilitymap.control | 5 ++ 4 files changed, 140 insertions(+) create mode 100644 contrib/pg_visibilitymap/Makefile create mode 100644 contrib/pg_visibilitymap/pg_visibilitymap--1.0.sql create mode 100644 contrib/pg_visibilitymap/pg_visibilitymap.c create mode 100644 contrib/pg_visibilitymap/pg_visibilitymap.control diff --git a/contrib/pg_visibilitymap/Makefile b/contrib/pg_visibilitymap/Makefile new file mode 100644 index 0000000..76cf1fa --- /dev/null +++ b/contrib/pg_visibilitymap/Makefile @@ -0,0 +1,19 @@ +# contrib/pg_visibilitymap/Makefile + +MODULE_big = pg_visibilitymap +OBJS = pg_visibilitymap.o $(WIN32RES) + +EXTENSION = pg_visibilitymap +DATA = pg_visibilitymap--1.0.sql +PGFILEDESC = "pg_visibilitymap - monitoring of visibility map" + +ifdef USE_PGXS +PG_CONFIG = pg_config +PGXS := $(shell $(PG_CONFIG) --pgxs) +include $(PGXS) +else +subdir = contrib/pg_visibilitymap +top_builddir = ../.. +include $(top_builddir)/src/Makefile.global +include $(top_srcdir)/contrib/contrib-global.mk +endif diff --git a/contrib/pg_visibilitymap/pg_visibilitymap--1.0.sql b/contrib/pg_visibilitymap/pg_visibilitymap--1.0.sql new file mode 100644 index 0000000..4817b2c --- /dev/null +++ b/contrib/pg_visibilitymap/pg_visibilitymap--1.0.sql @@ -0,0 +1,46 @@ +/* contrib/pg_visibilitymap/pg_visibilitymap--1.0.sql */ + +-- complain if script is sourced in psql, rather than via CREATE EXTENSION +\echo Use "CREATE EXTENSION pg_visibilitymap" to load this file. \quit + +-- Show visibility map information. +CREATE FUNCTION pg_visibilitymap(regclass, bigint) +RETURNS int4 +AS 'MODULE_PATHNAME', 'pg_visibilitymap' +LANGUAGE C STRICT; + +-- Show page status information. +CREATE FUNCTION pg_page_flags(regclass, bigint) +RETURNS int4 +AS 'MODULE_PATHNAME', 'pg_page_flags' +LANGUAGE C STRICT; + +-- pg_visibilitymap shows the visibility map bits for each block in a relation +CREATE FUNCTION + pg_visibilitymap(rel regclass, blkno OUT bigint, mapbits OUT int4) +RETURNS SETOF RECORD +AS $$ + SELECT blkno, pg_visibilitymap($1, blkno) AS mapbits + FROM generate_series(0, pg_relation_size($1) / current_setting('block_size')::bigint - 1) AS blkno; +$$ +LANGUAGE SQL; + +-- pg_visibility shows the visibility map bits and page-level bits for each +-- block in a relation. this is more expensive than pg_visibilitymap since +-- we must read all of the pages. +CREATE FUNCTION + pg_visibility(rel regclass, blkno OUT bigint, mapbits OUT int4, + pagebits OUT int4) +RETURNS SETOF RECORD +AS $$ + SELECT blkno, pg_visibilitymap($1, blkno) AS mapbits, + pg_page_flags($1, blkno) AS pagebits + FROM generate_series(0, pg_relation_size($1) / current_setting('block_size')::bigint - 1) AS blkno; +$$ +LANGUAGE SQL; + +-- Don't want these to be available to public. +REVOKE ALL ON FUNCTION pg_visibilitymap(regclass, bigint) FROM PUBLIC; +REVOKE ALL ON FUNCTION pg_page_flags(regclass, bigint) FROM PUBLIC; +REVOKE ALL ON FUNCTION pg_visibilitymap(regclass) FROM PUBLIC; +REVOKE ALL ON FUNCTION pg_visibility(regclass) FROM PUBLIC; diff --git a/contrib/pg_visibilitymap/pg_visibilitymap.c b/contrib/pg_visibilitymap/pg_visibilitymap.c new file mode 100644 index 0000000..9ffc7e1 --- /dev/null +++ b/contrib/pg_visibilitymap/pg_visibilitymap.c @@ -0,0 +1,70 @@ +/*------------------------------------------------------------------------- + * + * pg_visibilitymap.c + * display contents of a visibility map and page level bits + * + * contrib/pg_visibilitymap/pg_visibilitymap.c + *------------------------------------------------------------------------- + */ +#include "postgres.h" + +#include "access/visibilitymap.h" +#include "funcapi.h" +#include "storage/bufmgr.h" + +PG_MODULE_MAGIC; + +PG_FUNCTION_INFO_V1(pg_visibilitymap); +PG_FUNCTION_INFO_V1(pg_page_flags); + +Datum +pg_visibilitymap(PG_FUNCTION_ARGS) +{ + Oid relid = PG_GETARG_OID(0); + int64 blkno = PG_GETARG_INT64(1); + int32 mapbits; + Relation rel; + Buffer vmbuffer = InvalidBuffer; + + rel = relation_open(relid, AccessShareLock); + + if (blkno < 0 || blkno > MaxBlockNumber) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("invalid block number"))); + + mapbits = (int32) visibilitymap_get_status(rel, blkno, &vmbuffer); + if (vmbuffer != InvalidBuffer) + ReleaseBuffer(vmbuffer); + + relation_close(rel, AccessShareLock); + PG_RETURN_INT32(mapbits); +} + +Datum +pg_page_flags(PG_FUNCTION_ARGS) +{ + Oid relid = PG_GETARG_OID(0); + int64 blkno = PG_GETARG_INT64(1); + int32 pagebits; + Relation rel; + Buffer buffer; + Page page; + + rel = relation_open(relid, AccessShareLock); + + if (blkno < 0 || blkno > MaxBlockNumber) + ereport(ERROR, + (errcode(ERRCODE_INVALID_PARAMETER_VALUE), + errmsg("invalid block number"))); + + buffer = ReadBuffer(rel, blkno); + LockBuffer(buffer, BUFFER_LOCK_SHARE); + + page = BufferGetPage(buffer); + pagebits = (int32) (((PageHeader) (page))->pd_flags); + + UnlockReleaseBuffer(buffer); + relation_close(rel, AccessShareLock); + PG_RETURN_INT32(pagebits); +} diff --git a/contrib/pg_visibilitymap/pg_visibilitymap.control b/contrib/pg_visibilitymap/pg_visibilitymap.control new file mode 100644 index 0000000..f1686eb --- /dev/null +++ b/contrib/pg_visibilitymap/pg_visibilitymap.control @@ -0,0 +1,5 @@ +# pg_visibilitymap extension +comment = 'examine the visibility map (VM)' +default_version = '1.0' +module_pathname = '$libdir/pg_visibilitymap' +relocatable = true -- 2.5.4 (Apple Git-61)