postgresql/contrib/pg_freespacemap/pg_freespacemap--1.0.sql
Tom Lane 458857cc9d Throw a useful error message if an extension script file is fed to psql.
We have seen one too many reports of people trying to use 9.1 extension
files in the old-fashioned way of sourcing them in psql.  Not only does
that usually not work (due to failure to substitute for MODULE_PATHNAME
and/or @extschema@), but if it did work they'd get a collection of loose
objects not an extension.  To prevent this, insert an \echo ... \quit
line that prints a suitable error message into each extension script file,
and teach commands/extension.c to ignore lines starting with \echo.
That should not only prevent any adverse consequences of loading a script
file the wrong way, but make it crystal clear to users that they need to
do it differently now.

Tom Lane, following an idea of Andrew Dunstan's.  Back-patch into 9.1
... there is not going to be much value in this if we wait till 9.2.
2011-10-12 15:45:03 -04:00

25 lines
871 B
PL/PgSQL

/* contrib/pg_freespacemap/pg_freespacemap--1.0.sql */
-- complain if script is sourced in psql, rather than via CREATE EXTENSION
\echo Use "CREATE EXTENSION pg_freespacemap" to load this file. \quit
-- Register the C function.
CREATE FUNCTION pg_freespace(regclass, bigint)
RETURNS int2
AS 'MODULE_PATHNAME', 'pg_freespace'
LANGUAGE C STRICT;
-- pg_freespace shows the recorded space avail at each block in a relation
CREATE FUNCTION
pg_freespace(rel regclass, blkno OUT bigint, avail OUT int2)
RETURNS SETOF RECORD
AS $$
SELECT blkno, pg_freespace($1, blkno) AS avail
FROM generate_series(0, pg_relation_size($1) / current_setting('block_size')::bigint - 1) AS blkno;
$$
LANGUAGE SQL;
-- Don't want these to be available to public.
REVOKE ALL ON FUNCTION pg_freespace(regclass, bigint) FROM PUBLIC;
REVOKE ALL ON FUNCTION pg_freespace(regclass) FROM PUBLIC;