Partitioning Guidelines with Incremental Aggregation
Partitioning Guidelines with Incremental Aggregation
When you use incremental aggregation in a session with multiple partitions, the Integration Service creates one set of cache files for each partition.
Use the following guidelines when you change the number of partitions or the cache directory:
Change the cache directory for a partition.
If you change the directory for a partition and you want the Integration Service to reuse the cache files, you must move the cache files for the partition associated with the changed directory.
If you change the directory for the first partition, and you do not move the cache files, the Integration Service rebuilds the cache files for all partitions.
If you change the directory for partitions 2-
n
, and you do not move the cache files, the Integration Service rebuilds the cache files that it cannot locate.
Decrease the number of partitions.
If you delete a partition and you want the Integration Service to reuse the cache files, you must move the cache files for the deleted partition to the directory configured for the first partition. If you do not move the files to the directory of the first partition, the Integration Service rebuilds the cache files that it cannot locate.
If you increase the number of partitions, the Integration Service realigns the index and data cache files the next time you run a session. It does not need to rebuild the files.
Move cache files.
If you move cache files for a partition and you want the Integration Service to reuse the files, you must also change the partition directory. If you do not change the directory, the Integration Service rebuilds the files the next time you run a session.
Delete cache files.
If you delete cache files, the Integration Service rebuilds them the next time you run a session.
If you change the number of partitions and the cache directory, you may need to move cache files for both. For example, if you change the cache directory for the first partition and you decrease the number of partitions, you need to move the cache files for the deleted partition and the cache files for the partition associated with the changed directory.
