For each input row, the Integration Service queries the lookup source or cache based on the lookup ports and the lookup condition in the transformation.

If the transformation is uncached or uses a static cache, the Integration Service returns values from the lookup query.

If the transformation uses a dynamic cache, the Integration Service inserts the row into the cache when it does not find the row in the cache. When the Integration Service finds the row in the cache, it updates the row in the cache or leaves it unchanged. It flags the row as insert, update, or no change.

The Integration Service returns data from the query and passes it to the next transformation in the mapping.

If the transformation uses a dynamic cache, you can pass rows to a Filter or Router transformation to filter new rows to the target.