DB2 9 & 10 for z/OS Overview

Migration Planning WorkshopEXPLAIN Changes...• EXPLAIN tables must be in:– V8 or later format (Otherwise -20008, RC 2 is returned)– Unicode encoding scheme• Is preferred for V8 & V9 formats• Required for V10 format (Otherwise SQLCODE -878 returned)– DB2 10 Installation & Migration Guide – Chap. 2 – Converting EXPLAIN tables• EXPLAIN CAPTURE Special Register (defaults to NO)– Set to YES• Explainable SQL statements run normally and explain information is captured after eachstatement is prepared and executed– Set to EXPLAIN• Explainable SQL statements do not execute but explain information is captured duringprepare• Note that application logic may fail when expecting successful execution– Requires a PLAN_TABLE and DSN_STATEMENT_CACHE_TABLE• The DSNAEXP stored procedure is deprecated– This procedure allowed the EXPLAIN of a SQL statement with the authorization forthe statement– The EXPLAIN privilege or SQLADM should be used149© 2011 IBM Corporation