Re: Poor performance in Porting Oracle based applicatio

BTW, when you say that it's taking "double the time", what are we really
talking about? Is this the difference between 50 ms and 100 ms, or are we
talking about minutes? (smaller differences may be attributable to
differences in hardware.)

The output of vacuum analyze doesn't tell _me_ anything, but it does let
postgres examine your data so that it can be smart about how it does things.

Whatever you can explain about _what_ is actually taking a long time will
help. Take a look at the comments that were made in the thread (also going
on today) titled "Updates are slow.." -- much of that advice could be good
for you, too.

More info in:
1) schema
2) log the queries
3) hardware/OS differences (are your servers running on the same type of
machine?)

If you can't post the schema, then something else (some kind of test case)
that will show the problem would sure help.

-ron

> -----Original Message-----
> From: Roberto Nanamura [mailto:roberto(at)summa-tech(dot)com]
> Sent: Tuesday, June 11, 2002 12:23 PM
> To: Ron Snyder
> Cc: pgsql-general(at)postgresql(dot)org
> Subject: Re: [GENERAL] Poor performance in Porting Oracle
> based application to PostgreSQL
>
>
> Sorry, for not posting the schema. I have asked my manager
> about that and I am
> waiting for the response.
>
> I have just joined the project. I ran a vacuum verbose
> analyze. See the results
> attached.
>
> Ron Snyder wrote:
> >
> > I don't have any experience with taking weblogic from
> oracle to postgres,
> > but you might try posting some more details regarding the
> insert/update that
> > you are doing.
> >
> > I'd also recommend (since you're just at the beginning of
> your project?)
> > that you switch to postgres 7.2.1 instead of using 7.1.3.
> This will allow
> > you to run vacuums without locking the table.
> >
> > Have you run a vacuum analyze, as well?
> >
> > -ron
> >
> > > -----Original Message-----
> > > From: Roberto Nanamura [mailto:roberto(at)summa-tech(dot)com]
> > > Sent: Monday, June 10, 2002 12:05 PM
> > > To: pgsql-general(at)postgresql(dot)org
> > > Subject: [GENERAL] Poor performance in Porting Oracle based
> > > application to PostgreSQL
> > >
> > >
> > >
> > > Hi all,
> > >
> > > We are facing a performance degradation when we ported a
> > > Weblogic 6.0 sp2 (using
> > > BMP entity EJBs) from Oracle 8.1.7 to PostgreSQL 7.1.3 both
> > > using Linux RedHat.
> > > One of most insert/update intensive tasks is taking double
> > > the time it took in
> > > Oracle.
> > >
> > > Did anyone have this problem before? What are your
> > > experiences in porting an BMP
> > > EJB based application from Oracle to PostgreSQL? Is this just
> > > a problem of
> > > tuning or it is inherent to PostgreSQL? Can a well-tuned
> > > PostgreSQL be that
> > > slower than Oracle?
> > >
> > > Thanks for your attention,
> > >
> > > Roberto
> > >
>