You can build dimensions dynamically by adding header information to the top record of the data source and by specifying the location of the header record in the rules file.
The header record lists field definitions for each field. The field definition includes the field type, the field number, and the dimension name into which to load the fields. Figure 65, Header Record with Three Field Definitions illustrates the format of a header record:
If the file delimiter is a comma, enclose each field definition in quotation marks (" ").
After you set the header information in the data source, you must specify the location of the header information in the rules file. If a rules file refers to header information in a data source, Essbase uses the information in the data source—rather than the information in the rules file—to determine field types and dimensions.