The Generate Rules from DB Constraints dialog box is designed to download the existing foreign key constraint information from the source Oracle database and to construct suitable Extraction Set rules to enforce them. This function normally only needs to be done once - when the Extraction Set is first designed.
The foreign key rule information is stored in a separate file (given the .fkcon extension) and associated with the Extraction Set. This avoids the need to download the rule information each time the Set Designer loads the Extraction Set. The name of the current rule file can be found on the Rule Tools tab.
Please note that foreign keys can reference tables in other schemas. A rule generated
from such a "cross schema" constraint will have a slightly modified icon 
which contains a small X in the lower right hand corner.
Important Note: If the download of the constraint information seems to take a long time try setting the Data Dictionary Optimizer Hint on the Rule Tools Tab before activating this dialog box.
The Generate Rules from DB Constraints Rules dialog box is very easy to use. There are two large buttons located centrally toward the bottom of the dialog box. Press the Get the Rules button to download the foreign key constraints from the remote schemas. Once the constraints have downloaded add the rules to the Extraction Set by pressing the Add Selected Rules to Set button. The progress bars at the bottom of the dialog box indicate the progress of the download and the Stop button can be used at any time to interrupt a download in progress.
If new foreign key constraints have been added to the schema you can download and generate rules for them at any time. Duplicate rules will always be ignored.