postgresql/contrib/pg_stat_statements/pg_stat_statements--1.1--1.2.sql
Tom Lane f0d6f20278 Keep pg_stat_statements' query texts in a file, not in shared memory.
This change allows us to eliminate the previous limit on stored query
length, and it makes the shared-memory hash table very much smaller,
allowing more statements to be tracked.  (The default value of
pg_stat_statements.max is therefore increased from 1000 to 5000.)
In typical scenarios, the hash table can be large enough to hold all the
statements commonly issued by an application, so that there is little
"churn" in the set of tracked statements, and thus little need to do I/O
to the file.

To further reduce the need for I/O to the query-texts file, add a way
to retrieve all the columns of the pg_stat_statements view except for
the query text column.  This is probably not of much interest for human
use but it could be exploited by programs, which will prefer using the
queryid anyway.

Ordinarily, we'd need to bump the extension version number for the latter
change.  But since we already advanced pg_stat_statements' version number
from 1.1 to 1.2 in the 9.4 development cycle, it seems all right to just
redefine what 1.2 means.

Peter Geoghegan, reviewed by Pavel Stehule
2014-01-27 15:37:54 -05:00

44 lines
1.3 KiB
SQL

/* contrib/pg_stat_statements/pg_stat_statements--1.1--1.2.sql */
-- complain if script is sourced in psql, rather than via ALTER EXTENSION
\echo Use "ALTER EXTENSION pg_stat_statements UPDATE TO '1.2'" to load this file. \quit
/* First we have to remove them from the extension */
ALTER EXTENSION pg_stat_statements DROP VIEW pg_stat_statements;
ALTER EXTENSION pg_stat_statements DROP FUNCTION pg_stat_statements();
/* Then we can drop them */
DROP VIEW pg_stat_statements;
DROP FUNCTION pg_stat_statements();
/* Now redefine */
CREATE FUNCTION pg_stat_statements(IN showtext boolean,
OUT userid oid,
OUT dbid oid,
OUT queryid bigint,
OUT query text,
OUT calls int8,
OUT total_time float8,
OUT rows int8,
OUT shared_blks_hit int8,
OUT shared_blks_read int8,
OUT shared_blks_dirtied int8,
OUT shared_blks_written int8,
OUT local_blks_hit int8,
OUT local_blks_read int8,
OUT local_blks_dirtied int8,
OUT local_blks_written int8,
OUT temp_blks_read int8,
OUT temp_blks_written int8,
OUT blk_read_time float8,
OUT blk_write_time float8
)
RETURNS SETOF record
AS 'MODULE_PATHNAME', 'pg_stat_statements_1_2'
LANGUAGE C STRICT VOLATILE;
CREATE VIEW pg_stat_statements AS
SELECT * FROM pg_stat_statements(true);
GRANT SELECT ON pg_stat_statements TO PUBLIC;