The optimization strategies are dependent on the configuration
of the DB2® environment. You
need be aware of this configuration while you are designing performance
improvements.
Optimization strategies for intrapartition parallelism
The optimizer can choose an access plan to execute a query
in parallel within a single database partition if a degree of parallelism
is specified when the SQL statement is compiled.
Optimization strategies for MDC tables
If you create multidimensional clustering (MDC) tables,
the performance of many queries might improve, because the optimizer
can apply additional optimization strategies. These strategies are
primarily based on the improved efficiency of block indexes, but the
advantage of clustering on more than one dimension also permits faster
data retrieval.
Optimization strategies for partitioned tables
Data partition elimination refers to the database server's
ability to determine, based on query predicates, that only a subset
of the data partitions in a table need to be accessed to answer a
query. Data partition elimination is particularly useful when running
decision support queries against a partitioned table.