DB2 Version 10.1 for Linux, UNIX, and Windows

Automatic revalidation of database objects

Automatic revalidation is a mechanism whereby invalid database objects are automatically revalidated when accessed at run time.

A database object usually depends upon one or more different base objects. If the status of base objects on which the database object depends upon change in any important way, such as the base object being altered or dropped, the dependent database object becomes invalid. Invalid database objects must be revalidated before they can be used again. Revalidation is the process by which the DB2 software reprocesses the definition of an invalid dependent object so that the object is updated with the current state of its base objects, thereby turning the invalid dependent object back into a usable, valid object. Automatic revalidation is a mechanism whereby invalid database objects are automatically revalidated when accessed at run time.

In general, the database manager attempts to revalidate invalid objects the next time that those objects are used. Automatic revalidation is enabled through the auto_reval configuration parameter. By default, this registry variable is set to DEFERRED, except for databases upgraded from Version 9.5 or earlier, in which case auto_reval is set to DISABLED.

For information about the dependent objects that are impacted when an object is dropped, and when those dependent objects are revalidated, see DROP statement.

The following list shows the data definition language (DDL) statements for which automatic revalidation is currently supported:

ALTER MODULE DROP FUNCTION
ALTER MODULE DROP PROCEDURE
ALTER MODULE DROP TYPE
ALTER MODULE DROP VARIABLE
ALTER NICKNAME (altering the local name or the local type)
ALTER TABLE ALTER COLUMN
ALTER TABLE DROP COLUMN
ALTER TABLE RENAME COLUMN
CREATE OR REPLACE ALIAS
CREATE OR REPLACE FUNCTION
CREATE OR REPLACE NICKNAME
CREATE OR REPLACE PROCEDURE
CREATE OR REPLACE SEQUENCE
CREATE OR REPLACE TRIGGER
CREATE OR REPLACE VARIABLE
CREATE OR REPLACE VIEW
DROP FUNCTION
DROP NICKNAME
DROP PROCEDURE
DROP SEQUENCE
DROP TABLE
DROP TRIGGER
DROP TYPE
DROP VARIABLE
DROP VIEW
RENAME TABLE

You can use the ADMIN_REVALIDATE_DB_OBJECTS procedure to revalidate existing objects that have been marked invalid.