If an OUTER JOIN indicator was specified in at least one JOIN predicate of the QUERY specification, the number of underlying tables of the QUERY specification FROM clause must be precisely two, or the following must apply:
1. OUTER JOIN indicators are only specified for one of the tables specified in the FROM clause.
2. All joins of this table related to just one other table contain the OUTER JOIN INDICATOR.
3. No other joins contain an OUTER JOIN INDICATOR.
Try to add any missing OUTER JOIN indicators or to split the SQL statement into several SQL statements, or to achieve the desired effect by using QUERY expressions in the FROM clause.