for (Join join : ais.getJoins().values()) {
            
            // bug 931258: If parent has no external PK, flag this as an error. 
            if (join.getParent().getPrimaryKey() == null) {
                output.reportFailure(new AISValidationFailure(
                        new JoinParentNoExplicitPK (join.getParent().getName())));
                continue;
            }
            TableIndex parentPK= join.getParent().getPrimaryKey().getIndex();
            if (parentPK.getKeyColumns().size() != join.getJoinColumns().size()) {
                output.reportFailure(new AISValidationFailure(