DB2 Version 9.7 for Linux, UNIX, and Windows

Performance enhancements

Version 9.7 contains numerous performance enhancements that continue to make the DB2® data server an industrial-strength data server solution that is suitable for any size of organization.

The DB2 optimizer has been improved with the following enhancements:

Access plan reuse
Statement concentrator support
RUNSTATS sampling improvements for statistical views
The ALTER PACKAGE statement for applying optimization profiles
Cost model improvements for queries in partitioned database environments

In addition, faster data access and increased data concurrency is provided by the following enhancements:

Cursor stability (CS) isolation level with currently committed semantics
Scan sharing
Partitioned indexes on partitioned tables
Materialized query table (MQT) matching enhancements
The ability to store some inline LOB files in tables
I/O completion ports (IOCP) support on the AIX® operating system
Isolation level locking intent support in subselect and fullselect clauses
Availability of partitioned table data during roll-out operations
Queries with spatial data can run faster in partitioned database environments

Another enhancement extends the support of optimization guidelines to XML data. For more information, see Optimization profiles support guidelines for XML data.

You can now use the fcm_parallelism configuration parameter to control the degree of parallelism that is used for communication between members within a DB2 instance. For more information, see FCM parallelism support added.