For each source table, there must be a unique combination of fields in the key of the information structure. This means that there can never be two data records with the same value combination within one data object.

For each key field, the system establishes the field similarity between the reference field and the additional source fields.

The system fills the information structure with archive data using an "outer join" based on the field combination. The system writes a record for the data object if at least one of the source tables contains data.

When the system is filling an information structure, an incorrectly defined field catalog can cause a program termination. Read the long text in the error message Q6234. Here you can also find a detailed example of how to create field catalogs.

The source field entered directly in the field selection is also the reference field. The data type of the relevant field in the information structure is derived from this reference field. The fields entered under Additional Source Fields must be compatible with this type of reference field.