Re: BUG #2658: Query not using index
| От | Chris Browne |
|---|---|
| Тема | Re: BUG #2658: Query not using index |
| Дата | |
| Msg-id | 60d599gqcz.fsf@dba2.int.libertyrms.com обсуждение |
| Ответ на | Re: BUG #2658: Query not using index (Graham Davis <gdavis@refractions.net>) |
| Ответы |
Re: BUG #2658: Query not using index
|
| Список | pgsql-performance |
gdavis@refractions.net (Graham Davis) writes: > 40 seconds is much too slow for this query to run and I'm assuming > that the use of an index will make it much faster (as seen when I > removed the GROUP BY clause). Any tips? Assumptions are dangerous things. An aggregate like this has *got to* scan the entire table, and given that that is the case, an index scan is NOT optimal; a seq scan is. An index scan is just going to be slower. -- let name="cbbrowne" and tld="linuxdatabases.info" in String.concat "@" [name;tld];; http://cbbrowne.com/info/linux.html "The computer is the ultimate polluter: its feces are indistinguishable from the food it produces." -- Alan J. Perlis
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