Re: Problems with adding a is not null to a query.
От | Tim Uckun |
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Тема | Re: Problems with adding a is not null to a query. |
Дата | |
Msg-id | AANLkTinD_Bmgy34W70ywxXM0b1xOWBBEvR8hO95y9LzS@mail.gmail.com обсуждение исходный текст |
Ответ на | Re: Problems with adding a is not null to a query. (Tom Lane <tgl@sss.pgh.pa.us>) |
Ответы |
Re: Problems with adding a is not null to a query.
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Список | pgsql-bugs |
> With a table that large, you're probably going to need a larger stats > target in order to get reasonable estimates for low-frequency values. > Am I right in guessing that pg_stats.n_distinct is much too low for > the domain_id column? the domain_id is in the topical urls. A select count of domains shows that there are 700 domains, the pg_stats shows 170 which seems kind of low but maybe is not out of bounds because most domains are probably inactive. pg_stats on the consolidated_urls table shows a very low value for index_delta. There are 1.8 million records and the n_distinct for index_delta is 151. It's a floating point number so that seems weird. For index it's 818. Both of those numbers are wildly wrong I would think.
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