In addition to a join key, you must also configure a record index for each data source that feeds a join. A record index is a key that indicates to the record assembler how it can identify records from that source.
Creating a record index
You specify a record index for a data source in the source's editor. The following example describes how to create a record index for a record cache.
Join keys with multiple properties or dimensions
You can specify multiple properties or dimensions, called key components, for a single join key in order to join records based on more than one characteristic.