PG_MODULE_MAGIC;

pg_freespace(PG_FUNCTION_ARGS)

{

Oidrelid=PG_GETARG_OID(0);

uint32blkno=PG_GETARG_UINT32(1);

int64blkno=PG_GETARG_INT64(1);

int16freespace;

Relationrel;

rel=relation_open(relid,AccessShareLock);

if (!BlockNumberIsValid(blkno))

if (blkno<0||blkno>MaxBlockNumber)

ereport(ERROR,

(errcode(ERRCODE_INVALID_PARAMETER_VALUE),

errmsg("invalid block number")));

/* $PostgreSQL: pgsql/contrib/pg_freespacemap/pg_freespacemap.sql.in,v 1.10 2008/09/30 11:17:07 heikki Exp $ */

/* $PostgreSQL: pgsql/contrib/pg_freespacemap/pg_freespacemap.sql.in,v 1.11 2008/10/02 12:20:50 heikki Exp $ */

-- Adjust this setting to control where the objects get created.

SET search_path = public;

-- Register the C function.

CREATE OR REPLACE FUNCTION pg_freespace(regclass,int4)

CREATE OR REPLACE FUNCTION pg_freespace(regclass,bigint)

RETURNS int2

AS 'MODULE_PATHNAME', 'pg_freespace'

LANGUAGE C;

-- pg_freespace shows the recorded space avail at each block in a relation

CREATE OR REPLACE FUNCTION

pg_freespace(rel regclass, blkno OUTint4, avail OUT int2)

pg_freespace(rel regclass, blkno OUTbigint, avail OUT int2)

RETURNS SETOF RECORD

AS $$

SELECT blkno::int4, pg_freespace($1, blkno::int4) AS avail

SELECT blkno, pg_freespace($1, blkno) AS avail

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_freespace(regclass,int4) FROM PUBLIC;

REVOKE ALL ON FUNCTION pg_freespace(regclass,bigint) FROM PUBLIC;

REVOKE ALL ON FUNCTION pg_freespace(regclass) FROM PUBLIC;

<!-- $PostgreSQL: pgsql/doc/src/sgml/pgfreespacemap.sgml,v 2.4 2008/10/0210:26:51 heikki Exp $ -->

<!-- $PostgreSQL: pgsql/doc/src/sgml/pgfreespacemap.sgml,v 2.5 2008/10/0212:20:50 heikki Exp $ -->

<sect1 id="pgfreespacemap">

<title>pg_freespacemap</title>

<varlistentry>

<term>

<function>pg_freespace(rel regclass IN, blkno OUTint4, avail OUT int2)</function>

<function>pg_freespace(rel regclass IN, blkno OUTbigint, avail OUT int2)</function>

</term>

<listitem>

<para>

Displays the the amount of free space on each page of the relation,

according to the FSM. A set of <literal>(blknoint4, avail int2)</>

according to the FSM. A set of <literal>(blknobigint, avail int2)</>

tuples is returned, one tuple for each page in the relation.

</para>

</listitem>