Slow insert in GTT

  • From: Amir Gheibi <gheibia@xxxxxxxxx>
  • To: ORACLE-L <oracle-l@xxxxxxxxxxxxx>
  • Date: Wed, 25 Feb 2009 15:49:51 +0800

Hi listers,
What could cause an Insert in a Global Temporary Table takes a lot of time?
This is how I do the insert:

Insert into TT (...)
Select .. From ...

The insert is being done in a SP.
The Temp table is created with the "on commit preserve rows" option and
that's because the table is used later in the SP.

The select statement might returns 10,000 records.
I have used a couple of hints in the select statement and the "Append" hint
in the Insert (even though I don't like to use append as it locks the table)
but still have the issue.
I also understand that the PARALLEL hint will be ignored for inserts on
GTTs. So I can't use that either.

Any Idea, please?

One more thing, the select statement is built upon a join between another
temp table and a couple of permanent tables.

Thanks.
Amir

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