Re: Getting result set metadata without executing query? - Mailing list pgsql-novice

From Tom Ansley
Subject Re: Getting result set metadata without executing query?
Date
Msg-id 200207110826.54438.tansley@law.du.edu
Whole thread Raw
In response to Re: Getting result set metadata without executing query?  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Getting result set metadata without executing query?
List 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


pgsql-novice by date:

Previous
From: Philip Hallstrom
Date:
Subject: Re: web archiving
Next
From: Tom Lane
Date:
Subject: Re: Getting result set metadata without executing query?