I'm having a relatively weird problem: We've got a J2EE app running on JBoss (4.0.0) using MDBs to run some calculations in parallel and writing the results to a DB (v8). So far we've been using DB2 for our tests, but wanted to test the app with Oracle (v9.2). We left the app reading its input data from DB2 but switched the DataSource used for writing to be an OracleXADataSource.
Now the weird bit. The DB access would appear to be faster, but the overall throughput has gone way way way down. We can manage 30 calculations a second with DB2, but switching out the one DataSource to Oracle yields a mere 1 calculation per second. (This is on average based on all calculations done over about a minute - the actual throughput fluctuates on a second by second basis from 10 to 40 with DB2 and 0 to 10 with Oracle).
I've already had one colleague who has a much better understanding of Oracle check the DB settings and we're hauling in one of our Oracle big guns to check it out, because I'm fairly sure the problem will lie therein, however I wanted to throw this problem into the forum to see if anyone else has had similar experiences or has some tips where I might want to look.
Here's the DS declaration:
I'm running the app on some fairly well sized Windows 2k machines (dual Pentium 4 3Ghz / 4Gb RAM / SCSI HD). The Oracle DB is run on an identical machine, and both machines are directly connected via a GBit hub.
Any help / hints / tips are very much appreciated :D