DEALLOCATE COLLECTION statement

Use the DEALLOCATE COLLECTION statement to release memory for a collection variable that was previously allocated with the ALLOCATE COLLECTION statement.

This statement is an extension to the ANSI/ISO standard for SQL. Use this statement with ESQL/C.

Syntax


>>-DEALLOCATE COLLECTION--:variable----------------------------><

Element	Description	Restrictions	Syntax
variable	Name that identifies a typed or untyped collection variable for which to deallocate memory	Must be the name of the Informix® ESQL/C collection variable that has already been allocated	Name must conform to language-specific rules for names of variables

Usage

The DEALLOCATE COLLECTION statement frees all the memory that is associated with the Informix ESQL/C collection variable that variable identifies. You must explicitly release memory resources for a collection variable with DEALLOCATE COLLECTION. Otherwise, deallocation occurs automatically at the end of the program.

The DEALLOCATE COLLECTION statement releases resources for both typed and untyped collection variables.

Tip: The DEALLOCATE COLLECTION statement deallocates memory for Informix ESQL/C collection variables only. To deallocate memory for Informix ESQL/C row variables, use the DEALLOCATE ROW statement.

If you deallocate nonexistent collection variables or variables that are not Informix ESQL/C collection variables, you receive errors. After you deallocate a collection variable, you can use the ALLOCATE COLLECTION to reallocate resources and you can then reuse a collection variable.

This example shows how to deallocate resources with the DEALLOCATE COLLECTION statement for the untyped collection variable, a_set:

EXEC SQL BEGIN DECLARE SECTION;
   client collection a_set;
EXEC SQL END DECLARE SECTION;
. . .
EXEC SQL allocate collection :a_set;
. . .
EXEC SQL deallocate collection :a_set;

For a related example, see the related concept, Inserting into a Collection Cursor.