Before you partition a mapping, note the following rules and guidelines:
•Consider the types of transformations in the mapping and the order in which transformations appear so that you do not get unexpected results. You can partition a mapping if the Mapping Configuration task can maintain data consistency when it processes the partitioned data.
•For flat file partitioning, session performance is optimal with large source files. The load may be unbalanced if the amount of input data is small.
•When a Sequence Generator transformation is in a mapping with partitioning enabled, ensure that you set up caching in the Sequence Generator transformation. Otherwise, the sequence numbers the task generates for each partition are not consecutive.
•Sequence numbers generated by Normalizer and Sequence Generator transformations might not be sequential for a partitioned source, but they are unique.
•When a Sorter transformation is in a mapping with partitioning enabled, the task sorts data in each partition separately.
•A Sorter transformation must be placed before any Joiner transformation or Aggregator transformation that is configured to use sorted data.
•You cannot use in-out parameters for key range values.
•If your mapping has more than eight partitions, Mapping Configuration task performance might degrade. You can configure the Buffer Block Size and DTM Buffer Size advanced properties in the Mapping Configuration task to improve performance.
•On Linux, if a target table name includes a unicode character, you need to set the default locale to UTF-8 to support multibyte data. To set the default locale to UTF-8, see the following examples: