Data Validation Option uses joins in VALUE and OUTER_VALUE tests. To run VALUE and OUTER_VALUE tests on a table pair, you must join the tables based on the related keys in each table.
By default, Data Validation Option joins the tables with an inner equijoin and sorts the rows in the table. The join condition uses the following
Table A.column_name = Table B.column_name
If one of the tables in a table pair contains a large volume of data compared to the other table, you can increase test performance by designating the larger table as the detail source and the smaller table as the master source. Select the smaller table as Table A and the larger table as Table B. When the PowerCenter Integration Service determines whether to join two records, it compares each row of the master source against the detail source.
To increase performance of a table pair with two large tables, sort the input. When you run tests on tables with sorted records, the PowerCenter Integration Service minimizes disk input and output.
To further increase performance for large relational tables, configure the table pair so that the database sorts the records.