Key types

Fields that define the key fields in the Database Dictionary (Dbdict) of a file. These key fields create the indexes used in queries to make searching for records fast and efficient.

Key types allow or disallow certain values across all records within the file for the combined fields that comprise the key, and assist in maintaining data integrity by controlling the field values in a key. The key types include unique, no nulls, no duplicates, and nulls & duplicates. IR Expert uses separate keys.