Re: Make COUNT(*) Faster?
| От | Dawid Kuroczko |
|---|---|
| Тема | Re: Make COUNT(*) Faster? |
| Дата | |
| Msg-id | 758d5e7f050708083423c20c70@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: Make COUNT(*) Faster? (Rod Taylor <pg@rbt.ca>) |
| Ответы |
Re: Make COUNT(*) Faster?
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| Список | pgsql-sql |
On 7/8/05, Rod Taylor <pg@rbt.ca> wrote: > Create 2 sequences, one for counting tuple additions and one for > counting tuple deletions. > > When you INSERT a tuple, bump the "added" sequence (select nextval()); > > When you DELETE a tuple, bump the "deleted" sequence (select nextval()); > > To retrieve an approximate count, take the current value of both > sequences (select directly -- don't use currval) and subtract the > "deletes" from the "adds". Never thought of that! Good idea. :-) Regards, Dawid PS: There aren't any on ROLLBACK triggers, right? ;-)))
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