Partition Pruning Min/Max Optimization Fails when Parallel Query Run in Serial

(Doc ID 1941770.1)

Last updated on NOVEMBER 05, 2014

Applies to:

Oracle Database - Enterprise Edition - Version 11.2.0.1 and later
Information in this document applies to any platform.

Symptoms

Query execution takes very long time when there is no local index on the partition column and it was going for full table scan.

Test Case

Review trace file generated by event 10128.

Compare to running the same but with no_parallel instead of parallel.

If a select query with,
  1. range partitioned table
  2. uses MIN/MAX operator on partitioned key
  3. iterator uses MIn/MAX optimization
     PARTITION RANGE ALL MIN/MAX
  4. parallel query plan is run in serial
  5. all of the partitions are accessed
then you might be encountering this issue.

Cause

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