Free prepared statements
A prepared SQL statement occupies space in memory. With some database servers, it can consume space that the database server owns as well as space that belongs to the program. This space is released when the program terminates, but in general, you should free this space when you finish with it.
You can use the FREE statement to release this space. The FREE statement takes either the name of a statement or the name of a cursor that was declared for a statement name, and releases the space allocated to the prepared statement. If more than one cursor is defined on the statement, freeing the statement does not free the cursor.