Thank you … Are the calculations for triggering autovacuum dependent upon statistics generated by auto-anaylyze. In other words, if autoanalyze does not run at all, will autovac be able to run its math for threshold (updates & deletes) & scale factor (table rows) to do its thing? My understanding from the documentation is that it does not need autoanalyze stats. Thanks ---------------- From: Justin Pryzby On Wed, Feb 27, 2019 at 09:47:13AM -0500, Fd Habash wrote: > I have been able to locate four google search results with the same inquiry. What’ve been able to understand is … > > 1. If auto-vaccum is working as expected, stats collector does not nullify these values as part of a startup sequence or regular Maitenance. If a relation gets auto[vacuumed|analyzed], the timestamps should remain. > 2. A database engine crash or restart with ‘immediate’ option will cause the timestamps to nullify. > 3. Table never qualified for vacuuming based on auto-vacuum settings. Can you give an example ? If it's an empty inheritence parent (relkind=r), then it won't trigger autovacuum/analyze thresholds (but you should analyze it manually). Note that relkind=p "partitioned" tables don't have entries at all. https://www.postgresql.org/message-id/flat/20180503141430.GA28019%40telsasoft.com If it's never DELETEd from, then it won't trigger autovacuum (but may trigger autoanalyze). Justin |
