1. WHAT IS A FILTER TRANSFORMATION AND WHY IT IS AN ACTIVE ONE?
2. WHAT IS THE DIFFERENCE BETWEEN SOURCE QUALIFIER TRANSFORMATIONS SOURCE FILTER OPTION AND FILTER TRANSFORMATION?
28.Differentiate between Router and Filter Transformation?
29. What is a Filter Transformation and why it is an Active one?
A Filter transformation is an Active and Connected transformation that can filter rows in a mapping.
Only the rows that meet the Filter Condition pass through the Filter transformation to the next transformation in the pipeline. TRUE and FALSE are the implicit return values from any filter condition we set. If the filter condition evaluates to NULL, the row is assumed to be FALSE. The numeric equivalent of FALSE is zero (0) and any non-zero value is the equivalent of TRUE.
As an ACTIVE transformation, the Filter transformation may change the number of rows passed through it. A filter condition returns TRUE or FALSE for each row that passes through the transformation, depending on whether a row meets the specified condition. Only rows that return TRUE pass through this transformation. Discarded rows do not appear in the session log or reject files.