Prerequisites for using EXPLAIN snapshots in comparisons

Ensure that these prerequisites are met before using EXPLAIN snapshots to find and fix changes in multiple access plans or compare multiple access plans.

You use EXPLAIN snapshots when finding and fixing changes in these situations:

You also use EXPLAIN snapshots when comparing access plans in these situations:

An EXPLAIN snapshot in InfoSphere® Optim™ Query Workload Tuner is a set of EXPLAIN information that is collected at a point in time.

If the SQL statements run on DB2® for z/OS®:
  • In the Data Source Explorer, connect to a DB2 for z/OS subsystem that is configured for query workload tuning and where a license for IBM® InfoSphere Optim Query Workload Tuner is active.
  • You must have the following privilege on these tables:
    • SELECT, INSERT, UPDATE, and DELETE privileges on the following tables: DB2OSC.AOC_WAPC_SESSIONS, DB2OSC.AOC_WAPC_RS and DB2OSC.AOC_WAPC_EX
    • SELECT privilege on the following tables: DB2OSC.DSN_WCC_EV_HISTORY, DB2OSC.DSN_WCC_EP_HISTORY, DB2OSC.DSN_WCC_STMT_INSTS, DB2OSC.DSN_STATEMNT_TABLE, DB2OSC.DSN_WCC_STMT_RUNTM, and DB2OSC.DSN_WCC_STMT_TEXTS
    • SELECT privilege on the EXPLAIN tables (PLAN_TABLE and DSN_STATEMNT_TABLE) under schema DB2OSC
If the SQL statements run on DB2 for Linux, UNIX, and Windows:

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