Q: SQL*Loader Performance

I hope somebody can explain this one as my VAX system administrator and I are very confused.

I have two completely seperate Oracle databases / instances (RDBMS 7.0.16) running on a VAX 6620 (VMS 5.5). If I run a SQL*Loader job (loading 260,000 rows) while both databases are up and running, the load uses less CPU and clock time than when *only* the database that is being loaded is up and running!

To test this, I took the second database down and ran the load during a very quiet time (no other user or batch job running). The job took more time (CPU and clock) than when I ran the load during normal to light activity and both databases / instances running.

With both databases up and running, I get the following statistics:

Elapsed time was :        00:29:44.19
CPU time was:             00:16:26.82

With only one database up and running, my statistics are:

Elapsed time was:         00:41:00.58
CPU time was:             00:38:34.95

What gives? Any thoughts, theories, facts, or otherwise are greatly appreciated.

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Murray Kaiser                  | Usual gutless disclaimer..
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