Re: index usage on queries on inherited tables
От | Joseph Shraibman |
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Тема | Re: index usage on queries on inherited tables |
Дата | |
Msg-id | 4DB88690.5050701@selectacast.net обсуждение исходный текст |
Ответ на | Re: index usage on queries on inherited tables (Robert Haas <robertmhaas@gmail.com>) |
Ответы |
Re: index usage on queries on inherited tables
Re: index usage on queries on inherited tables Re: index usage on queries on inherited tables |
Список | pgsql-performance |
On 04/27/2011 04:32 PM, Robert Haas wrote: > In the first case, PostgreSQL evidently thinks that using the indexes > will be slower than just ignoring them. You could find out whether > it's right by trying it with enable_seqscan=off. My point is that this is just a problem with inherited tables. It should be obvious to postgres that few rows are being returned, but in the inherited tables case it doesn't use indexes. This was just an example. In a 52 gig table I have a "select id from table limit 1 order by id desc" returns instantly, but as soon as you declare a child table it tries to seq scan all the tables.
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