Re: Missed index opportunity for outer join?
От | Ron Mayer |
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Тема | Re: Missed index opportunity for outer join? |
Дата | |
Msg-id | 4395FF61.6060301@cheapcomplexdevices.com обсуждение исходный текст |
Ответ на | Re: Missed index opportunity for outer join? (Tom Lane <tgl@sss.pgh.pa.us>) |
Ответы |
Re: Missed index opportunity for outer join?
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Список | pgsql-performance |
Tom Lane wrote: > ...planner is actually going to choose based on the ultimate join cost, > not on the subplan costs... > > In this explanation, the reason for the change in plans over time could > be a change in the statistics for the other table. Is "facets" more > dynamic than "point_features"? In total rows changing it's more dynamic, but percentage-wise, it's less dynamic (point_features probably turns round 50% of it's rows in a day -- while facets turns over about 3% per day -- but facets is 1000X larger). Facets is a big table with rather odd distributions of values. Many of the values in the indexed columns show up only once, others show up hundreds-of-thousands of times. Perhaps an analyze ran and just randomly sampled differently creating different stats on that table?
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