Re: query planning different in plpgsql?

On Fri, Oct 23, 2009 at 11:38 AM, Michal J. Kubski <michal.kubski@cdt.pl>wrote:
>> I am running the following one and it takes 10 minutes in the procedure
>> when it is pretty fast standalone.
>>
>> # EXPLAIN ANALYZE SELECT m.domain_id, nsr_id FROM nsr_meta m, last_snapshot
>> l WHERE m.domain_id = l.domain_id;

Is it *really* just like that inside the stored procedure?  Usually
the reason for a difference in plan is that the procedure's query
references some variables of the procedure, which people think act
like constants but they don't.

Also, if you're executing the SELECT as a plpgsql FOR-loop, it will be
planned like a cursor, so the thing to compare against is
    explain [analyze] declare x cursor for select ...

            regards, tom lane