Pass-through SQL

Use pass-through SQL when the SQL statement that you enter is not valid inside a derived table. Pass-through SQL lets you use native SQL without any of the restrictions that the data source imposes on subqueries. This is because pass-through SQL query subjects are not processed as subqueries. Instead, the SQL for each query subject is sent directly to the data source where the query results are generated.

Because each query subject is sent to the data source as a separate statement rather than being optimized by IBM® Cognos® Framework Manager, performance is slower. Therefore, in choosing between native SQL and pass-through SQL, you must decide which is more important: performance or using SQL that is not permitted in a subquery.

Generally, you should use pass-through SQL only if you must create a query subject that contains constructs that are specific to a data source and that cannot be used inside a derived table, such as in a With or OrderBy clause.

SQL specified in Framework Manager and processed by the database, whether native or pass-through, must be completely self-contained. It must not reference anything outside of that SQL, such as database prompts, variables, or native formatting that would normally be supplied by the calling application.

For example, here is a systems-oriented report that contains the system date:


Note that the number sign (#) is reserved for macros and that column names must be unique. Framework Manager removes anything that is outside the number signs when running the macro.