Advanced tuning techniques
You can use several tuning techniques that go beyond the recommendations of the advisors and influence access plans directly.
Creating and deploying optimization hints for SQL statements that run on DB2 for z/OS
You can create, validate, and deploy an optimization hint for an SQL statement that runs on a DB2 for z/OS subsystem. With an optimization hint, you can set criteria to assist the DB2 optimizer to select the optimal execution plan for the SQL statement.
Creating and deploying optimization profiles for SQL statements that run on DB2 for Linux, UNIX, and Windows
You can use an optimization profile to influence directly how an access plan for an SQL statement is created. In the profile, you can specify the indexes to use, how to access tables that the SQL statement references, the join method to use, and other settings.
Overriding the selectivity (filter factors) that the DB2 Optimizer estimates for predicates
Use the
Override Selectivity
feature to override filter factors that the DB2 optimizer estimates for predicates in SQL statements that run on DB2 for z/OS, Version 11 new-function mode or later.
Related tasks
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Sharing the results of tuning single SQL statements
Gathering information about the environments in which SQL statements run on DB2 for z/OS
Related reference
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Preparing for tuning
Locations from which you can capture an SQL statement for single-query tuning
Working with analysis tools and advisors
Generating reports
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