Re: [GENERAL] query optimization

Kevin Duffy wrote:
>
> So here are the questions for the PSQL gurus:
>
> Is getsectypekey('CFD') executing for every join (or possible join)
> between positions_gsco and security?
>
> Causing a scan of security for every possible join.
>
> Does ' (select getsectypekey('CFD') ) ' cause the getsectype()
> function to be executed once and thus
>
> allowing the index on security to be used.
>
> And of couse '5' makes things simple. The index on security is used.
>
> Am I posting this in the right. If not please help me correct my error
> and point me to the correct spot.
>

Is the function stable or volatile?

As Scott Marlowe suggested, you need to look at the explain results to
find out what the plan is in each case.

klint.

--
Klint Gore
Database Manager
Sheep CRC
A.G.B.U.
University of New England
Armidale NSW 2350

Ph: 02 6773 3789
Fax: 02 6773 3266
EMail: kgore4@une.edu.au

--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general