Re: Created Index is not used
От | Kjeld Peters |
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Тема | Re: Created Index is not used |
Дата | |
Msg-id | 43FDC206.2090102@profiling-company.de обсуждение исходный текст |
Ответ на | Re: Created Index is not used (Markus Schaber <schabi@logix-tt.com>) |
Список | pgsql-performance |
Hi Markus, first of all thanks for your quick reply! Markus Schaber wrote: > Kjeld Peters wrote: >>Select and update statements are quite slow on a large table with more >>than 600,000 rows. The table consists of 11 columns (nothing special). >>The column "id" (int8) is primary key and has a btree index on it. >> >>The following select statement takes nearly 500ms: >> >>SELECT * FROM table WHERE id = 600000; > > > Known issue which is fixed in 8.X servers, postgreSQL sees your 600000 > as int4 literal and does not grasp that the int8 index works for it. > > SELECT * FROM table WHERE id = 600000::int8; > > should do it. After I appended "::int8" to the query, selecting the table takes only 40-50ms. That's a great performance boost! > Btw, you should update to 7.4.12, there are importand bug fixes and it > is upgradable "in place", without dumping and reloading the database. I guess I'll test an upgrade to version 8.1. Thanks again for your and Ragnar's help! Kjeld
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