HPlogo ALLBASE/SQL Advanced Application Programming Guide: HP 3000 MPE/iX Computer Systems

Chapter 11 Using the VALIDATE Statement

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When you run an application, ALLBASE/SQL automatically and transparently checks each section for validity before executing it. When a section is found to be invalid, ALLBASE/SQL revalidates it (if possible), then executes it. You may notice a slight delay as the revalidation takes place. To avoid the delay of runtime revalidation, you can re-preprocess the program or use the VALIDATE statement to revalidate the affected modules prior to runtime. Complete syntax for the VALIDATE statement is presented in the ALLBASE/SQL Reference Manual.

You may find it appropriate to use the VALIDATE statement after executing an UPDATE STATISTICS statement, since that statement will invalidate stored sections. If you issue both statements during a period of low activity for the DBEnvironment, the optimizer will have current statistics on which to base its calculations, with minimal performance degradation.

The validate statement will not revalidate sections that have never been validated under the F.0 release, for example, sections that have been migrated from a previous release. These sections can be revalidated by running the application to execute all its sections. An alternative is to recreate the module by repreprocessing the application. Thereafter, you can use the VALIDATE statement.

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