When DBA restrictions are applied to a request on a multi-segment structure, by default, the restrictions are added as WHERE conditions in the report request. When the DBAJOIN parameter is set ON, DBA restrictions are treated as internal to the file or segment for which they are specified, and are added to the join syntax.
This difference is important when the file or segment being restricted has a parent in the structure and the join is an outer or unique join.
When restrictions are treated as report filters, lower-level segment instances that do not satisfy them are omitted from the report output, along with their host segments. Since host segments are omitted, the output does not reflect a true outer or unique join.
When the restrictions are treated as join conditions, lower-level values from segment instances that do not satisfy them are displayed as missing values, and the report output displays all host rows.
For more information, see the Creating Reports With WebFOCUS Language manual.