postgresql/contrib/pgstattuple/pgstattuple--1.3.sql
Andres Freund 5850b20f58 Add pgstattuple_approx() to the pgstattuple extension.
The new function allows to estimate bloat and other table level statics
in a faster, but approximate, way. It does so by using information from
the free space map for pages marked as all visible in the visibility
map. The rest of the table is actually read and free space/bloat is
measured accurately.  In many cases that allows to get bloat information
much quicker, causing less IO.

Author: Abhijit Menon-Sen
Reviewed-By: Andres Freund, Amit Kapila and Tomas Vondra
Discussion: 20140402214144.GA28681@kea.toroid.org
2015-05-13 07:35:06 +02:00

96 lines
3.6 KiB
SQL

/* contrib/pgstattuple/pgstattuple--1.3.sql */
-- complain if script is sourced in psql, rather than via CREATE EXTENSION
\echo Use "CREATE EXTENSION pgstattuple" to load this file. \quit
CREATE FUNCTION pgstattuple(IN relname text,
OUT table_len BIGINT, -- physical table length in bytes
OUT tuple_count BIGINT, -- number of live tuples
OUT tuple_len BIGINT, -- total tuples length in bytes
OUT tuple_percent FLOAT8, -- live tuples in %
OUT dead_tuple_count BIGINT, -- number of dead tuples
OUT dead_tuple_len BIGINT, -- total dead tuples length in bytes
OUT dead_tuple_percent FLOAT8, -- dead tuples in %
OUT free_space BIGINT, -- free space in bytes
OUT free_percent FLOAT8) -- free space in %
AS 'MODULE_PATHNAME', 'pgstattuple'
LANGUAGE C STRICT;
CREATE FUNCTION pgstatindex(IN relname text,
OUT version INT,
OUT tree_level INT,
OUT index_size BIGINT,
OUT root_block_no BIGINT,
OUT internal_pages BIGINT,
OUT leaf_pages BIGINT,
OUT empty_pages BIGINT,
OUT deleted_pages BIGINT,
OUT avg_leaf_density FLOAT8,
OUT leaf_fragmentation FLOAT8)
AS 'MODULE_PATHNAME', 'pgstatindex'
LANGUAGE C STRICT;
CREATE FUNCTION pg_relpages(IN relname text)
RETURNS BIGINT
AS 'MODULE_PATHNAME', 'pg_relpages'
LANGUAGE C STRICT;
/* New stuff in 1.1 begins here */
CREATE FUNCTION pgstatginindex(IN relname regclass,
OUT version INT4,
OUT pending_pages INT4,
OUT pending_tuples BIGINT)
AS 'MODULE_PATHNAME', 'pgstatginindex'
LANGUAGE C STRICT;
/* New stuff in 1.2 begins here */
CREATE FUNCTION pgstattuple(IN reloid regclass,
OUT table_len BIGINT, -- physical table length in bytes
OUT tuple_count BIGINT, -- number of live tuples
OUT tuple_len BIGINT, -- total tuples length in bytes
OUT tuple_percent FLOAT8, -- live tuples in %
OUT dead_tuple_count BIGINT, -- number of dead tuples
OUT dead_tuple_len BIGINT, -- total dead tuples length in bytes
OUT dead_tuple_percent FLOAT8, -- dead tuples in %
OUT free_space BIGINT, -- free space in bytes
OUT free_percent FLOAT8) -- free space in %
AS 'MODULE_PATHNAME', 'pgstattuplebyid'
LANGUAGE C STRICT;
CREATE FUNCTION pgstatindex(IN relname regclass,
OUT version INT,
OUT tree_level INT,
OUT index_size BIGINT,
OUT root_block_no BIGINT,
OUT internal_pages BIGINT,
OUT leaf_pages BIGINT,
OUT empty_pages BIGINT,
OUT deleted_pages BIGINT,
OUT avg_leaf_density FLOAT8,
OUT leaf_fragmentation FLOAT8)
AS 'MODULE_PATHNAME', 'pgstatindexbyid'
LANGUAGE C STRICT;
CREATE FUNCTION pg_relpages(IN relname regclass)
RETURNS BIGINT
AS 'MODULE_PATHNAME', 'pg_relpagesbyid'
LANGUAGE C STRICT;
/* New stuff in 1.3 begins here */
CREATE FUNCTION pgstattuple_approx(IN reloid regclass,
OUT table_len BIGINT, -- physical table length in bytes
OUT scanned_percent FLOAT8, -- what percentage of the table's pages was scanned
OUT approx_tuple_count BIGINT, -- estimated number of live tuples
OUT approx_tuple_len BIGINT, -- estimated total length in bytes of live tuples
OUT approx_tuple_percent FLOAT8, -- live tuples in % (based on estimate)
OUT dead_tuple_count BIGINT, -- exact number of dead tuples
OUT dead_tuple_len BIGINT, -- exact total length in bytes of dead tuples
OUT dead_tuple_percent FLOAT8, -- dead tuples in % (based on estimate)
OUT approx_free_space BIGINT, -- estimated free space in bytes
OUT approx_free_percent FLOAT8) -- free space in % (based on estimate)
AS 'MODULE_PATHNAME', 'pgstattuple_approx'
LANGUAGE C STRICT;