For a table partitioned by the FIX hash partitioning method, you can specify an RDAREA in which data is to be stored or searched for by the hash key value. However, if you add an RDAREA to a table partitioned by the FIX hash partitioning method (HASHA to HASHF), the utility assumes the access procedure for a table partitioned by the flexible hash partitioning method during search operation. If this happens, the search performance decreases for the following SQL:

• Search operation specifies a partitioning key as the condition.
• The column specified in the GROUP BY clause contains all partitioning keys.

The figure below shows the relationship between rebalancing processing and the period during which search performance decreases. While rebalance processing is underway, the number of processes required for SQL execution increases.

Figure 10-6 Relationship between rebalance processing and the period during which search performance decreases

For a table partitioned by the flexible hash partitioning, the rebalance processing has no effect on the access procedure for a search operation.