System performance will be affected by the performance of the host or System i™ database server. Different database management systems have different performance features. SQL optimizers of different systems, for example, could behave differently with the same application. Check your host or System i database server system performance documentation for more information.

You might be able to improve performance by using the uncommitted read (UR) or no commit (NC) bind options, where available, to avoid journaling.

Note: When using UR, unjournaled data can only be read, not updated, and then only if blocking is set to ALL.

Depending on the application server and the lock granularity it provides, the isolation level used for a query or application might have a significant effect on performance. The database should have the appropriate level of normalization, effective use of indexes, and suitable allocation of database space. Performance can also be affected by the data types that you use, as described in the following sections.

Parent topic: DB2 Connect tuning