Re: 7.3.1 New install, large queries are slow

On Thu, 16 Jan 2003, Josh Berkus wrote:

> Roman,
>
> > > Hey, Roman, how many records in BatchDetail, anyway?
> >
> > 23 million.
>
> And MSSQL is returning results in 3 seconds?    I find that a bit hard
> to believe, unless this query is called repeatedly and that's the
> figure for the last call, where the records are being cached.   I'll
> have to look at your hardware descriptions again.
>
> > It seems to me that the big, big isolated problem is the index scan
> > on batchdetail.tranamount.
>
> Nope.  This was a misimpression caused by batchdetail waiting for a
> bunch of other processes to complete.  Sometimes the parallelizing
> gives me a wrong impression of what's holding up the query.  Sorry if I
> confused you.

I'm still not sure that it isn't a big part given that the time went down
by a factor of about 4 when index scans were disabled and a sequence scan
was done and that a sequence scan over the table with no other tables
joined looked to take about 5 minutes itself and the difference between
that seqscan and the big query was only about 20 seconds when
enable_indexscan was off unless I'm misreading those results.