Partition Exchange Loading (PEL) is a data warehousing technique that is useful when you are loading data into a large, partitioned table. By swapping the table that contains the data to be loaded with an empty partition in the partitioned table, the data appears in the target table instantaneously together with any indexes associated with it, giving you the ability to prepare, load and index data offline, and then have it instantly appear in the data warehouse.
Restrictions for Using PEL in Warehouse Builder
These are the restrictions for using PEL in Warehouse Builder:
- Only One Date Partition Key: Only one partition key column of DATE data type is allowed. Numeric partition keys are not supported in Warehouse Builder.
- Only Natural Calendar System: The current PEL method supports only the natural calendar system adopted worldwide. Specific business calendar systems with user-defined fiscal and quarter endings are currently not supported.
- All Data Partitions Must Be In the Same Tablespace: All partitions of a target (table, dimension, or cube) must be created in the same tablespace.
- All Index Partitions Must Be In the Same Tablespace: All indexes of a target (table, dimension, or cube) must be created in the same tablespace. However, the index tablespace can be different from the data tablespace.