_cost_equality_semi_join, Peoplesoft, performance issues

  • From: John Clarke <jclarke@xxxxxxxxxxxxxxx>
  • To: oracle-l@xxxxxxxxxxxxx
  • Date: Wed, 12 Jan 2005 11:39:36 -0500

I've recently taken on the role of a DBA for a Peoplesoft upgrade projec=
t and have a question about =5Fcost=5Fequality=5Fsemi=5Fjoin.

We're running Oracle on HP-UX 11.00, upgrading from Peoplesoft 7=
.5 to 8.<something>. During this little project, we'll be upgrading from=
 7.3.4 to 9iR2, upgrading HP-UX from 11.00 to 11i, and upgrading Peoples=
oft and its tools, but due to where we're starting and what sort of hard=
ware we're on, we need to upgrade from 7.3.4 to first, then upgr=
ade Peoplesoft, then upgrade HP-UX to 11i, then patch Oracle up to 9.2.0=
.5 or 6.

Anyway ...

Since we'll be running Peoplesoft 7.x against for a month or so,=
 we're in the middle of doing performance/load testing with the version =
combination. We've found a handful of performance issues that are relate=
d to us setting =5Fcost=5Fequality=5Fsemi=5Fjoin to FALSE, the non-defau=
lt value.

We did this b/c we've found documentation recommending doing this, plus =
a handful of postings in various places have done this against

My understanding is that =5Fcost=5Fequality=5Fsemi=5Fjoin needed to be s=
et to FALSE to circumvent a bug that happens during the Peoplesoft upgra=
de process, but I'm not sure since my sources are varied and unreliable.

Does anyone have experience with this parameter against, specifi=
cally in the context of Peoplesoft=3F If so, I'd be curious to see what =
sorts of behavior you've seen.




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