Database Reference
In-Depth Information
Setting up the Lookup transformation
When you create the Lookup transformation, you can configure it to cache the data. Cach-
ing the data makes the processing faster, as the data is stored internally after the cache is
created. Once you choose to cache the data, the Lookup transformation caches the data
from the file or table once. Then, based on the condition defined, the lookup sends the out-
put value. As the data gets stored internally, processing becomes faster as it does not need
to check the lookup condition in the file or database. Integration Service queries the cache
memory instead of checking the file or table to fetch the required data.
When you choose to create the cache, Integration Service creates cache files in the
$PMCacheDir
default directory. The cache is created automatically and is also deleted
automatically once the processing is complete. We will discuss what cache is later in the
chapter.
