Autovacuum

• https://www.postgresql.org/docs/current/routine-vacuuming.html

select category,name,setting,unit,source,min_val,max_val from pg_settings where category = 'Autovacuum';
  category  |                name                 |  setting  | unit |       source       | min_val |  max_val
------------+-------------------------------------+-----------+------+--------------------+---------+------------
 Autovacuum | autovacuum                          | on        |      | default            |         |
 Autovacuum | autovacuum_analyze_scale_factor     | 0.05      |      | configuration file | 0       | 100
 Autovacuum | autovacuum_analyze_threshold        | 50        |      | default            | 0       | 2147483647
 Autovacuum | autovacuum_freeze_max_age           | 200000000 |      | default            | 100000  | 2000000000
 Autovacuum | autovacuum_max_workers              | 3         |      | configuration file | 1       | 262143
 Autovacuum | autovacuum_multixact_freeze_max_age | 400000000 |      | default            | 10000   | 2000000000
 Autovacuum | autovacuum_naptime                  | 15        | s    | configuration file | 1       | 2147483
 Autovacuum | autovacuum_vacuum_cost_delay        | 2         | ms   | default            | -1      | 100
 Autovacuum | autovacuum_vacuum_cost_limit        | 200       |      | configuration file | -1      | 10000
 Autovacuum | autovacuum_vacuum_scale_factor      | 0.1       |      | configuration file | 0       | 100
 Autovacuum | autovacuum_vacuum_threshold         | 50        |      | default            | 0       | 2147483647
(11 rows)

select category,name,setting,unit,source,min_val,max_val from pg_settings where category = 'Autovacuum';
  category  |                name                 |  setting  | unit | source  | min_val |  max_val
------------+-------------------------------------+-----------+------+---------+---------+------------
 Autovacuum | autovacuum                          | on        |      | default |         |
 Autovacuum | autovacuum_analyze_scale_factor     | 0.1       |      | default | 0       | 100
 Autovacuum | autovacuum_analyze_threshold        | 50        |      | default | 0       | 2147483647
 Autovacuum | autovacuum_freeze_max_age           | 200000000 |      | default | 100000  | 2000000000
 Autovacuum | autovacuum_max_workers              | 3         |      | default | 1       | 262143
 Autovacuum | autovacuum_multixact_freeze_max_age | 400000000 |      | default | 10000   | 2000000000
 Autovacuum | autovacuum_naptime                  | 60        | s    | default | 1       | 2147483
 Autovacuum | autovacuum_vacuum_cost_delay        | 2         | ms   | default | -1      | 100
 Autovacuum | autovacuum_vacuum_cost_limit        | -1        |      | default | -1      | 10000
 Autovacuum | autovacuum_vacuum_scale_factor      | 0.2       |      | default | 0       | 100
 Autovacuum | autovacuum_vacuum_threshold         | 50        |      | default | 0       | 2147483647
(11 rows)

select count(*) from pg_stat_activity where query like 'autovacuum:%';
 count
-------
     0
(1 row)

SELECT
  schemaname, relname,
  last_vacuum, last_autovacuum,
  vacuum_count, autovacuum_count
FROM pg_stat_user_tables;

Activites

• Read Understanding autovacuum in Amazon RDS for PostgreSQL environments, 2020: https://aws.amazon.com/blogs/database/understanding-autovacuum-in-amazon-rds-for-postgresql-environments/
• Read https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/Appendix.PostgreSQL.CommonDBATasks.Autovacuum.html
• DataFileRead
• Understand EXPLAIN output

Related terms

• PostgreSQL VACUUM
• pg_database
• Cache hit ratio
• pg database

See also

• VACUUM: PostgreSQL VACUUM, Autovacuum, pg_database, pg_stat_activity, Redshift VACUUM
• SQL, NewSQL, RDMS: GraphQL (2015), SQLite, select, insert, select count, Distributed SQL, TablePlus, Cache hit ratio, pg_stat_user_tables, EXPLAIN, Index (PostgreSQL), DDL, SQL/MED, Group by, List users, SQL Injection, SQLAlchemy, CREATE USER, CREATE ROLE, EXPLAIN, ALTER DATABASE, REVOKE, NOLOCK, NOWAIT, EXISTS, Unique constraint, .sql
• PostgreSQL: pg_dump, pg_restore, pgAdmin, pg_config, psql, pg_ctl, pg_isready, initdb, Role, Schema, DBeaver, Navicat, DataGrip, OmniDB, Adminer, docker-compose.xml PostgreSQL, PostgreSQL version, PostgreSQL logs, postgresql.conf, pg_hba.conf, $HOME/.pg_service.conf, Create database (PostgreSQL), Create user, createdb, GRANT, pg_stat, PostgreSQL VACUUM, EXPLAIN, pg stat activity, Autovacuum, ALTER DATABASE, PostgreSQL statistics collector, Shared buffers, EXPLAIN (PostgreSQL), EXPLAIN ANALYZE, Bitmap scan, EXPLAIN VERBOSE, EXPLAIN VERBOSE (PostgresSQL), WAL, ALTER USER, CREATE ROLE, CREATE USER, \du, show users, \l, The Statistics Collector, pganalyze, cron.schedule, Master, pg_tables, PostgreSQL replication, CREATE, SET, TOAST, PgBouncer, Restore DB, Index, meta-commands, Table, foreign table, Schema, Sequence, Views, materialized view, Table Partitioning, monitoring, PostgreSQL System Administration Functions, PostgreSQL extension, privileges, logging, PGTune, PostgreSQL parameter tunning, PostgreSQL modules, pgbench, PostgreSQL users, catalogs