AUTOVACUUMの設定
SELECT name, setting
FROM pg_settings
WHERE name LIKE '%autovacuum%';
autovacuum が on であること- 他の数値も異常な値でないこと(どう考えても実行されない閾値とか)
AUTOVACUUMの最終実行日時
SELECT relname, last_autovacuum,last_autoanalyze FROM pg_stat_user_tables
WHERE
last_autovacuum is not NULL OR
last_autoanalyze is not NULL;
テーブル毎のオプション
SELECT relname, reloptions
FROM pg_class
WHERE array_length(reloptions, 1) IS NOT NULL;
{autovacuum_enabled=false} が設定されていると、AUTOVACUUMされない
AUTOVACUUM実行対象のテーブル一覧
WITH vbt AS (SELECT setting AS autovacuum_vacuum_threshold FROM
pg_settings WHERE name = 'autovacuum_vacuum_threshold'),
vsf AS (SELECT setting AS autovacuum_vacuum_scale_factor FROM
pg_settings WHERE name = 'autovacuum_vacuum_scale_factor'),
fma AS (SELECT setting AS autovacuum_freeze_max_age FROM pg_settings WHERE name = 'autovacuum_freeze_max_age'),
sto AS (select opt_oid, split_part(setting, '=', 1) as param,
split_part(setting, '=', 2) as value from (select oid opt_oid, unnest(reloptions) setting from pg_class) opt)
SELECT '"'||ns.nspname||'"."'||c.relname||'"' as relation,
pg_size_pretty(pg_table_size(c.oid)) as table_size,
age(relfrozenxid) as xid_age,
coalesce(cfma.value::float, autovacuum_freeze_max_age::float) autovacuum_freeze_max_age,
(coalesce(cvbt.value::float, autovacuum_vacuum_threshold::float) +
coalesce(cvsf.value::float,autovacuum_vacuum_scale_factor::float) * c.reltuples)
AS autovacuum_vacuum_tuples, n_dead_tup as dead_tuples FROM
pg_class c join pg_namespace ns on ns.oid = c.relnamespace
join pg_stat_all_tables stat on stat.relid = c.oid join vbt on (1=1) join vsf on (1=1) join fma on (1=1)
left join sto cvbt on cvbt.param = 'autovacuum_vacuum_threshold' and c.oid = cvbt.opt_oid
left join sto cvsf on cvsf.param = 'autovacuum_vacuum_scale_factor' and c.oid = cvsf.opt_oid
left join sto cfma on cfma.param = 'autovacuum_freeze_max_age' and c.oid = cfma.opt_oid
WHERE c.relkind = 'r' and nspname <> 'pg_catalog'
AND (age(relfrozenxid) >= coalesce(cfma.value::float, autovacuum_freeze_max_age::float)
OR coalesce(cvbt.value::float, autovacuum_vacuum_threshold::float) +
coalesce(cvsf.value::float,autovacuum_vacuum_scale_factor::float) *
c.reltuples <= n_dead_tup)
ORDER BY age(relfrozenxid) DESC LIMIT 50;
👇こちらから拝借
docs.aws.amazon.com
参考
qiita.com
