The analysis tools can help you understand the structure
of an SQL statement, understand the access path for that statement,
test indexes before creating them, and compare access paths before
and after following recommendations from advisors.
Formatting SQL statements
The Query Tuner Workflow Assistant can
format an SQL statement so that you can better understand the structure
of that statement.
Generating visual representations of access plans
The Query Tuner Workflow Assistant can
display the access plan for a statement as a diagram. The diagram
provides cost and cardinality estimates for each step in the plan.
Browsing access plans with the Access Plan Explorer
Use the Access Plan Explorer to find the most expensive components of an access
plan in a format that lets you sort by cost and see relationships between
components.
Virtually testing recommended indexes and indexes that you propose You can test recommended indexes
and indexes that you propose without first creating them. The results
of each test show you whether the indexes improve the performance
of the current SQL statement, the estimated disk space that would
be required for the indexes, and whether the DB2® optimizer would use the indexes in the access
path for the current SQL statement.