Difference between revisions of "PostgreSQL VACUUM"

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  FROM [[pg_stat_user_tables]];
 
  FROM [[pg_stat_user_tables]];
  
  select count(*) from [[pg_stat_activity]] where query like 'autovacuum:%';
+
  [[select count]](*) from [[pg_stat_activity]] where query like 'autovacuum:%';
  
  

Revision as of 17:10, 5 August 2021

PostgreSQL VACUUM garbage-collect and optionally analyze a database.

VACUUM reclaims storage occupied by dead tuples.


Examples:

  • VACUUM (VERBOSE, ANALYZE) my_table;


SELECT
  schemaname, relname,
  last_vacuum, last_autovacuum,
  vacuum_count, autovacuum_count
FROM pg_stat_user_tables;
select count(*) from pg_stat_activity where query like 'autovacuum:%';


PosgreSQL recommend that active production databases be vacuumed frequently (at least nightly), in order to remove dead rows. [1]

VACUUM causes a substantial increase in I/O traffic.

Related terms

See also

  • https://www.postgresql.org/docs/current/sql-vacuum.html
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