Table Procedure Examples, Design, and Use › Access Methods for Selected Records › Unique Access Strategies for Entry, Path, and Auxiliary Records[ › Unique Access Methods for Entry Records

Unique Access Methods for Entry Records

For entry records, the method used to locate unique record occurrences is determined by which fields were selected as unique keys for that record type. An entry record can be either a CALC type record, a member of a (preferably mandatory/automatic) system-owned index, or both.

When the entry record access mode is CALC and is not a member of a system-owned index:

• The access mode for the record type is CALC if all of the unique keys fields selected in Quick Bridge match the CALC key fields exactly
• Otherwise, the record type is accessed using an area sweep

When the entry record is a member of a system-owned index:

• The access mode for the record type is also CALC if the record has a CALC access mode and all fields selected in Quick Bridge match the CALC key fields exactly
• Otherwise, the access mode for the record type is INDEX SET USING, if all fields selected in Quick Bridge match the sort elements of the index set exactly. The INDEX SET USING access mode requires that the unique key fields, that make up the index, are specified in the same order as the sort elements of the index set are defined in the network schema. Otherwise, the record type is accessed by walking through the index.

When the record type is accessed using an area sweep or by walking an index, the values passed to the table procedure are compared to the values in the current record occurrence. The area sweep or index walk continues until the values match.

The rules defined on the previous page anchor the query to a single occurrence of the entry record.