why do we use vaccum command in PostgreSQL exactly? -


vacuum reclaims storage occupied deleted tuples. in normal postgresql operation, tuples deleted or obsoleted update not physically removed table; remain present until vacuum done. therefore it's necessary vacuum periodically, on frequently-updated tables.

this got man page. want know cases required.

if delete rows or update them, vacuum required free space re-use. postgresql automatically autovacuum, not common need manually run vacuum.

you might manually run vacuum after updating large proportion of table, if you're going big update.


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