On Wed, 26 Jun 2002 17:34:47 +0200
Alvar Freude <alvar@xxxxxxxxxxx> wrote:
> Hi,
>
> -- Eric <emayo@xxxxxxxxxxx> wrote:
>
> > If I perform the following 2 selects, the first one is EXTREMELY slow
> > where the 2nd one is very fast.
>
> [...]
>
> > Why would 2 be so much faster? I have ran the EXPLAIN on this and index
> > scans are being used.
>
> I guess, the first query has to search for all ol.orderid the equivalent
> o.orderid; the second variant only has to search for '1234' in each
> ?.orderid, which is much faster.
You are right. And this type of optimising are not yet implemented.
Tom said it in the prior discussions.
Regards,
Masaru Sugawara
---------------------------(end of broadcast)---------------------------
TIP 3: if posting/reading through Usenet, please send an appropriate
subscribe-nomail command to majordomo@xxxxxxxxxxxxxx so that your
message can get through to the mailing list cleanly
|
