Changing the type of SQL

When choosing the type of SQL in which to generate a data source query subject, you must weigh the following factors and decide which are most important.

Type	Advantage	Disadvantage
Cognos® SQL	Cognos SQL improves query subject performance; for example, by removing unused elements at query time. SQL works on any supported database.	You cannot enter non-standard SQL.
Native SQL	Performance is optimized across all related query subjects. You can use SQL that is specific to your database.	You cannot use SQL that the data source does not support for subqueries. The SQL may not work on a different database type.
Pass- Through SQL	You can enter any SQL supported by the database.	There is no opportunity for Framework Manager to automatically optimize performance. The SQL may not work on a different data source.

Type

Advantage

Disadvantage

Cognos® SQL

Cognos SQL improves query subject performance; for example, by removing unused elements at query time.

SQL works on any supported database.

You cannot enter non-standard SQL.

Native SQL

Performance is optimized across all related query subjects.

You can use SQL that is specific to your database.

You cannot use SQL that the data source does not support for subqueries.

The SQL may not work on a different database type.

Pass- Through SQL

You can enter any SQL supported by the database.

There is no opportunity for Framework Manager to automatically optimize performance.

The SQL may not work on a different data source.