The transform function must take at least one parameter which must take either of two forms:
| LEFT | formatted like any of the setofdatasets. This indicates the first dataset in the setofdatasets. |
| ROWS(LEFT) | formatted like any of the setofdatasets. This indicates a record set made up of all records from any dataset in the setofdatasets that match the joincondition--this may not include all the datasets in the setofdatasets, depending on which jointype is specified. |
The format of the resulting output record set must be the same as the input datasets.