Note:

Any recomputation of a Link operation requires the Rich Client module to address the server engine and fetch the new record. This means that using too many Link operations may be costly in terms of server interaction. Therefore, it is recommended that you limit use of the Link operation. In many cases you may be able to substitute the Link operation with a Data control – a selection control like a combo box that displays the value of a range field taken from a table.

You can also use an Inner Join operation instead. In this case, the operation is fetched from the database along with the Main source and sent to the Rich Client module as a single chunk of data.