I have a user running a query that runs in 20 minutes using one date range
but takes hours and evenutally fails with ORA-1555 on a much smaller date
range. The number of rows in the smaller date range is also much smaller.
The query uses bind variables for the dates and the execution plan is
identical for both date ranges. One of the tables contains hudreds of
millions of rows and is partitioned by month. The smaller date range that
returns the ORA-1555 also happens to include the current month. I suspect
what's happening is that the current partition is being updated while the
query is running and it's going back to the rollback segments to get the
correct version of rows that changed after the query started. The ORA-1555
is a dead giveaway to me. The problem is my manager wants more proof. Is
there a session level statistic that will show how many times it had to go
to the RBS to get the correct version of a row?
--
Chuck
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Received on Thu Apr 22 2004 - 12:15:10 CDT
