Re: hint unique result fro union

On Aug 16, 2006, at 8:23 AM, Matteo Bertini wrote:

> Hello all!
>
> I'm quite new to pg, but I'm using it quite a lot in the last few
> monts.
>
> Deeping in new features, I found a question: is it possible to hint
> an unique result from a select?
>
> Mainly, thinking about partitions, I'd like to create a small,
> frequently accessed partition and a big, rarely accessed partition.
>
> I'd like to hint pg to stop the query on the parent partition at
> the first found item (and so hint not to analyze all the childs),
> because I know the index I'm using is unique.
>
> Possible? Usefull?
>

"select foo from bar limit 1" ?

I don't know if there's any guaranteed ordering of results from
a union query, though, and that's what a query on a set of
inherited tables will expand to, pretty much.

Cheers,
Steve