WHERE Clause Driving Table

The Where Clause Driving Table property tells the Analytical Engine what type of column is preferred in a qualification of a WHERE clause when generating SQL. One SQL pass usually joins fact tables and lookup tables on certain ID columns. When a qualification is defined on such a column, the Analytical Engine can use the column in either the fact table or the lookup table. In certain databases, like Teradata and RedBrick, a qualification on the lookup table can achieve better performance. By setting the Where Clause Driving Table property to Use Lookup Table, the Analytical Engine always tries to pick the column from the lookup table.

If Use lookup table is selected, but there is no lookup table in the FROM clause for the column being qualified on, the Analytical Engine does not add the lookup table to the FROM clause. To make sure that a qualification is done on a lookup table column, the DSS Star Join property should be set to use Partial star join.

Levels at Which You Can Set This

Database instance, report, and template