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Analyzing Queries with GENPLAN [ ALLBASE/SQL Performance Guidelines ] MPE/iX 5.0 Documentation


ALLBASE/SQL Performance Guidelines

Analyzing Queries with GENPLAN 

The GENPLAN statement can be useful in determining the way to write a
SELECT, UPDATE, or DELETE statement for maximum performance.  GENPLAN
lets you see the optimizer's access plan for one ALLBASE/SQL statement at
a time.  Issue the GENPLAN statement in ISQL, then simply do a SELECT on
the temporary table SYSTEM.PLAN within the same transaction.  A
knowledgeable user may be able to use this information to formulate
queries differently or make other design changes to improve performance.

Whenever users have a performance concern about a query, they can use the
GENPLAN statement to generate the access plan for the query and display
the plan information by doing a SELECT on the temporary table
SYSTEM.PLAN. By using GENPLAN and SELECT statements, users can easily
investigate the performance question.

Refer to the ALLBASE/SQL Release F.0 Application Programming Bulletin 
chapter, "Analyzing Queries with GENPLAN," and the ALLBASE/SQL Reference 
Manual for more information about the GENPLAN statement.



MPE/iX 5.0 Documentation