Обсуждение: 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

On Mon, 10 Jun 2002 12:05:26 -0700
"Roberto Nanamura" <roberto@summa-tech.com> wrote:
> 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.

"It goes slow, what's wrong?"

We'll need more information in order to be able to make any meaningful
comments. Can you post the relevent parts of the schema? How much data
are you storing, how many updates/inserts are being executed? How large is
the performance degredation? If relevant, post the query plan for the
problematic queries (use EXPLAIN).

Cheers,

Neil

--
Neil Conway <neilconway@rogers.com>
PGP Key ID: DB3C29FC

Neil Conway <nconway@klamath.dyndns.org> writes:
> "Roberto Nanamura" <roberto@summa-tech.com> wrote:
>> 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.

> We'll need more information in order to be able to make any meaningful
> comments. Can you post the relevent parts of the schema? How much data
> are you storing, how many updates/inserts are being executed? How large is
> the performance degredation? If relevant, post the query plan for the
> problematic queries (use EXPLAIN).

And there are the usual questions: have you vacuum analyzed?  Have you
done any tuning (installing appropriate indexes, etc)?  Finally, I'd
certainly recommend an update to PG 7.2.1...

            regards, tom lane