https://yousysadmin.com/tags/aws/ Recent content in Aws on YouSysAdmin Hugo en YouSysAdmin Fri, 09 Oct 2026 11:13:56 +0300 https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/ Fri, 09 Oct 2026 11:00:00 +0300 https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/ <blockquote> <p>This note was written for PostgreSQL 13–18.<br> On older versions some columns of system views may differ. When in doubt, check the documentation for your version.<br> PostgreSQL 19 is still in beta/RC (release expected in October 2026). Where it changes something relevant, it is marked as &ldquo;PG19 (beta)&rdquo;.</p> </blockquote> <p>Legend used in the explanations:</p> <p>🟢 normal<br> 🟡 worth a look<br> 🔴 a problem that requires action</p> <h2 id="contents">Contents</h2> <ol> <li><a href="https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/#1-how-autovacuum-works-briefly">How autovacuum works (briefly)</a></li> <li><a href="https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/#2-current-autovacuum-settings">Current autovacuum settings</a></li> <li><a href="https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/#3-what-autovacuum-is-doing-right-now">What autovacuum is doing right now</a></li> <li><a href="https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/#4-dead-rows-and-vacuum-history-per-table">Dead rows and vacuum history per table</a></li> <li><a href="https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/#5-transaction-id-wraparound">Transaction ID wraparound</a></li> <li><a href="https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/#6-what-prevents-vacuum-from-removing-rows">What prevents vacuum from removing rows</a></li> <li><a href="https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/#7-table-and-index-sizes">Table and index sizes</a></li> <li><a href="https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/#8-bloat">Bloat</a></li> <li><a href="https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/#9-indexes-unused-duplicate-invalid">Indexes: unused, duplicate, invalid</a></li> <li><a href="https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/#10-general-database-health">General database health</a></li> <li><a href="https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/#11-locks">Locks</a></li> <li><a href="https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/#12-heavy-queries-pg_stat_statements">Heavy queries (pg_stat_statements)</a></li> <li><a href="https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/#13-replication-and-wal">Replication and WAL</a></li> <li><a href="https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/#14-checkpoints-and-io">Checkpoints and I/O</a></li> <li><a href="https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/#15-what-to-monitor-and-alert-thresholds">What to monitor and alert thresholds</a></li> <li><a href="https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/#16-configuration-recommendations">Configuration recommendations</a></li> <li><a href="https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/#17-routine-maintenance">Routine maintenance</a></li> <li><a href="https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/#18-partitioning">Partitioning</a></li> <li><a href="https://yousysadmin.com/posts/postgres-autovacuum-and-maintenance/#19-managed-postgresql-in-the-clouds">Managed PostgreSQL in the clouds</a></li> </ol> <hr> <h2 id="1-how-autovacuum-works-briefly">1. How autovacuum works (briefly)</h2> <p>PostgreSQL does not overwrite a row on <code>UPDATE</code> or <code>DELETE</code>. The old row version stays on disk as a <strong>dead tuple</strong> until <code>VACUUM</code> removes it. This is called MVCC.</p>