Specifies the value or field name. If Source Field ID is "0", this field is editable for constant value or for Text variables. If Source Field ID is not "0", the program retrieves field name and field is not editable.
Specifies a key index. Keys are used for better performance during filtering. The program can only use one key for a table. This means that the Key Index does not need to be specified for all lines. The Key Index can only be set on the first line.
Note:
The key should comprise all filtered fields if it is possible, or comprise as many of the field used in the filter as possible.