Appendix A. DB2 II V8.2 performance enhancements 433
agent. Intra-partition parallelism can improve query performance, assuming
adequate resources are available.
Intra-partition parallelism is enabled as follows:
򐂰 Set the INTRA_PARALLEL database manager configuration parameter to
YES.
򐂰 Set the MAX_QUERYDEGREE database manager configuration parameter
to a value greater than 1.
򐂰 Set the DFT_DEGREE database configuration parameter to a value greater
than 1, or set the special register CURRENT DEGREE. If you set the
DFT_DEGREE parameter to ANY, the default level of intra-partition
parallelism equals the number of processors on the computer.
Inter-partition parallelism in a DPF environment with local data
Figure A-3 shows inter-partition parallelism support before and after DB2 II V8.2
for federated queries accessing local data in a DPF environment.
Figure A-3 Inter-partition parallelism in a DPF environment with local data
In a DPF environment with federated queries that reference both local and
nickname data, the federated server can distribute the remote data to each of the
database partitions.
Note: Intra-partition parallelism is not dependent on the setting of the
DB2_FENCED wrapper option. It applies to both trusted and fenced mode
operations.
In DB2 II V8.1,
nickname data and
partitioned data can
only be joined serially
at the coordinator
partition.
In DB2 II 8.2, nickname
data can be distributed
to all partitions. Joins to
local partitioned data
can execute in parallel.
Nickname data
Local partitioned data

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