Replace repeated execution of dynamic SQL with a temporary query

This tip is closely related to tip #7. If you don't wish to store lots of queries, or you can't build them until your application is running, you can still benefit from many of the advantages of stored queries by using temporary queries. Temporary queries are exactly like regular querydef objects, except that they are unnamed (i.e., use "" [zero length string]) to create them. They have the added benefit of requiring no cleanup when you've finished using them (apart from closing them if you wish to regain their resources before your application ends), and they don't appear in the queries section of the database container for any other user.