Re: immutable functions vs. join for lookups ?

On 4/21/05, Enrico Weigelt <weigelt(at)metux(dot)de> wrote:
> * Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> <snip>
> > Yeah, I was actually thinking about a two-step process: inline the
> > function to produce somethig equivalent to a handwritten scalar
> > sub-SELECT, and then try to convert sub-SELECTs into joins.
>
> ... back to my original question ...
>
> What kind of query should I use ?
> Is a join better than a function ?

It appears that JOINs are usually faster. So if performance is an
important issue, go with JOIN (and VIEWs probably). Functions are nicer
(in terms off look and feel).

Regards,
Dawid