On Fri, Aug 14, 2020 at 3:04 PM Justin Pryzby <pry...@telsasoft.com> wrote:
> Due to the over-estimated rowcount, the planner believes that (more) rows > will > be output (sooner) than they actually are: > > -> Nested Loop Semi Join (cost=47.11..31367302.81 ROWS=611586 > width=336) (actual time=47.098..97236.123 ROWS=25 loops=1) > > So it thinks there's something to be saved/gained by using a plan that has > a > low startup cost. But instead, it ends up running for a substantial > fraction > of the total (estimated) cost. > > Got it. Is there any way to address this other than re-writing the query? (Statistics? Or something else?) > As for the "explain is more expensive than the query", that could be due to > timing overhead, as mentioned here. Test with "explain (timing off)" ? > https://www.postgresql.org/docs/12/using-explain.html#USING-EXPLAIN-CAVEATS > > Good call--explain with the timing off showed about the same time as the actual query. Thanks! Ken > -- > Justin > -- AGENCY Software A Free Software data system By and for non-profits *http://agency-software.org/ <http://agency-software.org/>* *https://demo.agency-software.org/client <https://demo.agency-software.org/client>* ken.tan...@agency-software.org (253) 245-3801 Subscribe to the mailing list <agency-general-requ...@lists.sourceforge.net?body=subscribe> to learn more about AGENCY or follow the discussion.
