Oracle 7.3 Parallel query 'Partiion Elimination' question

I have a problem with verifying the partition elimination of a standard partitioned view set up:

I have 2 identical tables, with a time based partition key of month:

Both tables have a check constraint on their partition key date to ensure rows within each are valid for the month to which they each relate.

A view has been set up which combines these 2 tables by 'SELECT * ... UNION ALL SELECT * ...' I've set both tables to be 'parallel aware', there are 10 parallel servers and the machine has 2 cpu's. Optimiser mode is CHOOSE.

When using the 'explain plan' on a query which accesses the view which will only select rows on just one of the underlying table partitions, by the date of the partition key, I expect to see a FILTER operation, to confirm partition elimination is taking place. However, although I can see that the 2 base tables are being queried in parallel from the output of explain plan, I don't see the expected FILTER so the partition elimination isn't happening. ie. Both tables are undergoing a FULL scan (in parallel) - but the second table scan should be unnecessary because the parser should make use of the existence of the check constraint to 'know' in advance that no rows on that table can possibly match.

Any ideas as to why partition elimination isn't happening?

Thanks in anticipation of your help.

Mark Received on Tue May 12 1998 - 17:37:04 CDT