Access methods that prevent direct row access

Certain access methods prevent Db2 from using direct row access.

Parallelism

Begin program-specific programming interface information. Direct row access and parallelism are mutually exclusive. If a query qualifies for both direct row access and parallelism, direct row access is used. If direct row access fails, Db2 does not revert to parallelism; instead it reverts to the backup access type (as designated by column ACCESSTYPE in the PLAN_TABLE). This might result in a table space scan. To avoid a table space scan in case direct row access fails, add an indexed column to the predicate.

RID list processing

Direct row access and RID list processing are mutually exclusive. If a query qualifies for both direct row access and RID list processing, direct row access is used. If direct row access fails, Db2 does not revert to RID list processing; instead it reverts to the backup access type. End program-specific programming interface information.