SEQCACH in macro DSN6SPRM
Specifies whether the sequential mode is to be used to read cached data from a 3990 controller. Valid values are BYPASS and SEQ.
If you specify BYPASS, DB2® prefetch bypasses the cache.
The default value, SEQ, means that DB2 prefetch uses sequential access for read activity. Many sites gain a performance benefit by specifying SEQ.
Recommendation: Specify SEQ if you have current disk devices with
good cache sizes, especially if the units are Enterprise Storage System (ESS) or RAMAC Virtual Array (RVA).
This subsystem parameter is deprecated in DB2 10.
