Re: Getting result set metadata without executing query?
От | Tom Ansley |
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Тема | Re: Getting result set metadata without executing query? |
Дата | |
Msg-id | 200207110826.54438.tansley@law.du.edu обсуждение исходный текст |
Ответ на | Re: Getting result set metadata without executing query? (Tom Lane <tgl@sss.pgh.pa.us>) |
Ответы |
Re: Getting result set metadata without executing query?
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Список | pgsql-novice |
I have..... SELECT * FROM foo where true = false; Is this as good as the answer below or does it do an entire table scan? Cheers Tom Ansley On Wednesday 10 July 2002 07:45 am, Tom Lane wrote: > Marc Ramirez <mrami@mrami.homeunix.org> writes: > > Is this possible with PostgreSQL? > > SELECT * FROM foo LIMIT 0 > > works in recent releases, though I think not before 7.1 or so. > > You'd want to avoid anything that involves a SORT step, though, > since it's not truly "not executing the query", just abandoning > it as soon as the first output row has been generated internally. > > regards, tom lane > > ---------------------------(end of broadcast)--------------------------- > TIP 3: if posting/reading through Usenet, please send an appropriate > subscribe-nomail command to majordomo@postgresql.org so that your > message can get through to the mailing list cleanly
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