PostgreSQL autovacuum forecast

autovacuum_forecast.sql

WITH rel_set AS (
	SELECT
		oid
	,	CASE split_part(
				split_part(array_to_string(reloptions, ','), 'autovacuum_vacuum_threshold=', 2)
			,	','
			,	1
			)
			WHEN '' THEN NULL
			ELSE
				split_part(
					split_part(array_to_string(reloptions, ','), 'autovacuum_vacuum_threshold=', 2)
				,	','
				,	1
				)::bigint
		END rel_av_vac_threshold
	,	CASE split_part(
				split_part(array_to_string(reloptions, ','), 'autovacuum_vacuum_scale_factor=', 2)
			,	','
			,	1
			)
			WHEN '' THEN NULL
			ELSE
				split_part(
					split_part(array_to_string(reloptions, ','), 'autovacuum_vacuum_scale_factor=', 2)
				,	','
				,	1
				)::numeric
		END rel_av_vac_scale_factor
	FROM
		pg_class
)
SELECT
	psut.schemaname "schema"
,	psut.relname table_name
,	to_char(psut.last_vacuum, 'YYYY-MM-DD HH24:MI') last_vacuum
,	to_char(psut.last_autovacuum, 'YYYY-MM-DD HH24:MI') last_autovacuum
,	to_char(c.reltuples, '9G999G999G999') n_tup
,	to_char(psut.n_dead_tup, '9G999G999G999') dead_tup
,	to_char(
		coalesce(rs.rel_av_vac_threshold, current_setting('autovacuum_vacuum_threshold')::bigint) + coalesce(
			rs.rel_av_vac_scale_factor
		,	current_setting('autovacuum_vacuum_scale_factor')::numeric
		) * c.reltuples
	,	'9G999G999G999'
	) av_threshold
,	CASE
		WHEN coalesce(rs.rel_av_vac_threshold, current_setting('autovacuum_vacuum_threshold')::bigint) + coalesce(
				rs.rel_av_vac_scale_factor
			,	current_setting('autovacuum_vacuum_scale_factor')::numeric
			) * c.reltuples < psut.n_dead_tup
			THEN '*'
		ELSE ''
	END expect_av
FROM
	pg_stat_user_tables psut
JOIN
	pg_class c
		ON psut.relid = c.oid
JOIN
	rel_set rs
		ON psut.relid = rs.oid
ORDER BY
	c.reltuples DESC;

autovacuum_forecast_extended.sql

-- show autovacuum forecast extended
-- nspname - the namespace of the table
-- relname - the table name
-- reltuples - total number of tuples
-- n_dead_tup - number of dead tuples needing to be vacuumed
-- v_threshold - autovacuum threshold for dead tuples
-- n_mod_since_analyze - number of tuples modified since last analyze
-- a_threshold - autoanalyze threshold for dead tuples
-- caf - custom autoanalyze factor
-- cat - custom autoanalyze threshold
-- cvt - custom autovacuum threshold
-- cvf - custom autoanalyze factor
-- gaf - global autoanalyze factor
-- gat - gloval autovacuum threshold
-- gvf - global autovacuum factor
-- gvt - global autovacuum threshold
WITH raw_data AS (
	SELECT
		pg_namespace.nspname
	,	pg_class.relname
	,	pg_class.oid relid
	,	pg_class.reltuples
	,	pg_stat_all_tables.n_dead_tup
	,	pg_stat_all_tables.n_mod_since_analyze
	,	(
			SELECT
				split_part(x, '=', 2)
			FROM
				unnest(pg_class.reloptions) q(x)
			WHERE
				x ~ '^autovacuum_analyze_scale_factor='
		) c_analyze_factor
	,	(
			SELECT
				split_part(x, '=', 2)
			FROM
				unnest(pg_class.reloptions) q(x)
			WHERE
				x ~ '^autovacuum_analyze_threshold='
		) c_analyze_threshold
	,	(
			SELECT
				split_part(x, '=', 2)
			FROM
				unnest(pg_class.reloptions) q(x)
			WHERE
				x ~ '^autovacuum_vacuum_scale_factor='
		) c_vacuum_factor
	,	(
			SELECT
				split_part(x, '=', 2)
			FROM
				unnest(pg_class.reloptions) q(x)
			WHERE
				x ~ '^autovacuum_vacuum_threshold='
		) c_vacuum_threshold
	,	to_char(pg_stat_all_tables.last_vacuum, 'YYYY-MM-DD HH24:MI:SS') last_vacuum
	,	to_char(pg_stat_all_tables.last_autovacuum, 'YYYY-MM-DD HH24:MI:SS') last_autovacuum
	FROM
		pg_class
	JOIN
		pg_namespace
			ON pg_class.relnamespace = pg_namespace.oid
	LEFT JOIN
		pg_stat_all_tables
			ON pg_class.oid = pg_stat_all_tables.relid
	WHERE
		n_dead_tup IS NOT NULL AND
		nspname NOT IN ('information_schema', 'pg_catalog') AND
		nspname NOT LIKE 'pg_toast%' AND
		pg_class.relkind = 'r'
)
, data AS (
	SELECT
		*
	,	coalesce(raw_data.c_analyze_factor, current_setting('autovacuum_analyze_scale_factor'))::double precision analyze_factor
	,	coalesce(raw_data.c_analyze_threshold, current_setting('autovacuum_analyze_threshold'))::double precision analyze_threshold
	,	coalesce(raw_data.c_vacuum_factor, current_setting('autovacuum_vacuum_scale_factor'))::double precision vacuum_factor
	,	coalesce(raw_data.c_vacuum_threshold, current_setting('autovacuum_vacuum_threshold'))::double precision vacuum_threshold
	FROM
		raw_data
)
SELECT
	relid
,	nspname
,	relname
,	reltuples
,	n_dead_tup
,	round(reltuples * vacuum_factor + vacuum_threshold) v_threshold
,	n_mod_since_analyze
,	round(reltuples * analyze_factor + analyze_threshold) a_threshold
,	c_analyze_factor caf
,	c_analyze_threshold cat
,	c_vacuum_factor cvf
,	c_vacuum_threshold cvt
,	analyze_factor gaf
,	analyze_threshold gat
,	vacuum_factor gvf
,	vacuum_threshold gvt
,	last_vacuum
,	last_autovacuum
FROM
	data
ORDER BY
	n_dead_tup DESC;