1
0
mirror of https://github.com/postgres/postgres.git synced 2025-07-26 01:22:12 +03:00
Files
config
contrib
adminpack
auth_delay
auto_explain
btree_gin
btree_gist
chkpass
citext
cube
dblink
dict_int
dict_xsyn
dummy_seclabel
earthdistance
file_fdw
fuzzystrmatch
hstore
intagg
intarray
isn
lo
ltree
oid2name
pageinspect
passwordcheck
pg_archivecleanup
pg_buffercache
pg_freespacemap
Makefile
pg_freespacemap--1.0.sql
pg_freespacemap--unpackaged--1.0.sql
pg_freespacemap.c
pg_freespacemap.control
pg_standby
pg_stat_statements
pg_test_fsync
pg_test_timing
pg_trgm
pg_upgrade
pg_upgrade_support
pgbench
pgcrypto
pgrowlocks
pgstattuple
seg
sepgsql
spi
sslinfo
start-scripts
tablefunc
tcn
test_parser
tsearch2
unaccent
uuid-ossp
vacuumlo
xml2
Makefile
README
contrib-global.mk
doc
src
.gitignore
COPYRIGHT
GNUmakefile.in
Makefile
README
README.git
aclocal.m4
configure
configure.in
postgres/contrib/pg_freespacemap/pg_freespacemap.c

45 lines
993 B
C

/*-------------------------------------------------------------------------
*
* pg_freespacemap.c
* display contents of a free space map
*
* contrib/pg_freespacemap/pg_freespacemap.c
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "funcapi.h"
#include "storage/freespace.h"
PG_MODULE_MAGIC;
Datum pg_freespace(PG_FUNCTION_ARGS);
/*
* Returns the amount of free space on a given page, according to the
* free space map.
*/
PG_FUNCTION_INFO_V1(pg_freespace);
Datum
pg_freespace(PG_FUNCTION_ARGS)
{
Oid relid = PG_GETARG_OID(0);
int64 blkno = PG_GETARG_INT64(1);
int16 freespace;
Relation rel;
rel = relation_open(relid, AccessShareLock);
if (blkno < 0 || blkno > MaxBlockNumber)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("invalid block number")));
freespace = GetRecordedFreeSpace(rel, blkno);
relation_close(rel, AccessShareLock);
PG_RETURN_INT16(freespace);
}