In a complex table, use options in the

Table Properties

dialog box to define a hierarchical relationship among the records on which the table is based. In a data map, a complex table mirrors the hierarchy of records or segments in the associated data source, such as an IMS database or sequential data set.

A complex table combines information into one table that, in a more normalized form, would reside in two or more tables.

You can define complex tables based on multiple related records, such as parent and child segments in an IMS database or parent and child records in a sequential data set. However, to retain the hierarchical linkage information for an IMS unload file, sequential file, or VSAM source or target, use simple single-record tables and sequencing fields that PowerExchange can generate when you import the data source into PowerCenter. File processing and data extraction are then faster, because column data in parent tables is not repeated.

The following table lists the data sources, with the associated access methods, that support complex tables: