Posted: Wed Aug 21, 2002 12:43 am
What exactly do you mean by a cross reference table? DataStage processes data row by row. It can perform reference lookups where it obtains a value typically from the row being processed, and uses that value to request one or more rows from another table, for example SELECT col1, col2, col3 FROM table WHERE col1 = ?;
Graphically, this is achieved using a reference input link to a Transformer stage. The second and subsequent input links to such a stage type are automatically reference input links, though it is possible to change later, but only one input can stream the rows being processed. The Transformer stage generates the value (in a "key expression") which is used to search for rows in the table on the other end of the reference input link. Depending on the stage type on the other end of the link it may or may not be possible to return more than one row. Only the ODBC and UV stage types can return more than one row.
Graphically, this is achieved using a reference input link to a Transformer stage. The second and subsequent input links to such a stage type are automatically reference input links, though it is possible to change later, but only one input can stream the rows being processed. The Transformer stage generates the value (in a "key expression") which is used to search for rows in the table on the other end of the reference input link. Depending on the stage type on the other end of the link it may or may not be possible to return more than one row. Only the ODBC and UV stage types can return more than one row.