> Tom Lane <[EMAIL PROTECTED]> wrote: >> Michael Fuhr <[EMAIL PROTECTED]> writes: > > On Tue, Oct 25, 2005 at 04:56:11PM -0700, chester c young wrote: > >> in php (for example) it's frequently nice to get the structure of > >> table without any data, > > > Have you considered "SELECT * FROM mytable LIMIT 0"? > > Indeed.
i think i misled: the goal is to retrieve _one_ row where the value of each attribute is null. this can be done laborously using meta data, but is done quite niftily using a left join against one row. > > I see the same behavior in the latest 8.1beta code. Maybe one of > > the developers will comment on whether optimizing that is a simple > > change, a difficult change, not worth changing because few people > > find a use for it, or a behavior that can't be changed because of > > something we're not considering. > > Not worth changing --- why should we expend cycles (even if it only > takes a few, which isn't clear to me offhand) on every join query, to > detect what's simply a brain-dead way of finding out table structure? again, the goal is a quick way to retrieve one row from a table where each attribute value is null, NOT to get the table structure. > I can't think of any realistic scenarios for a constant-false join > clause. i would like a better idea on how to retrieve one row from a table where the value of each attribute is null - i felt this a perfectly good use of sql. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ---------------------------(end of broadcast)--------------------------- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
