This form is displayed when you connect to a database and there have been some database descriptor file changes since you last connected to this database.
Database Structure Changes
Operation
From the pulldown list choose the required option:
- Apply changes directly to database (recommended)
- Script database changes to text file
- Apply changes to data dictionary
Apply changes directly to database
This is the usual way of applying database structure modifications. It remains the recommended method for administrators who don’t have any special need to generate scripts.
On pressing the Continue button, Impact applies the changes directly to the database. No further action is required.
Script database changes to text file
Choosing this option and pressing Continue will cause Impact to generate a SQL script and prompt you for a location to store it.
You should see the following message: “Successfully exported the database changes. Once you have applied these scripted changes to your Impact database ensure you re-import the changes and update Impact's database dictionary to match the physical database structure. Failure to do so may result in Impact generating invalid SQL statements and/or reporting database errors.”
The file may be viewed in any editor. If you attempt to modify the script, you should take extreme caution and you should back up the database before applying it.
You should now exit Impact and not restart until you have run the script on the database.
Apply changes to data dictionary
This option must only be used if you have already generated a script, as described above, and applied it. In these circumstances, the Database Structure Changes form will not normally be displayed, so you must manually initiate this process. When logging in to Impact as ADMIN, it is best to skip the Database Integrity Check this time. Use Database > Administration and from the menu choose Tables > Import > Table Description. You must then locate the DBS file which describes the necessary database structure (this is normally called “ipds_ddb.dbs” and often resides in the Impact program folder).
When you press Continue, Impact updates its database dictionary without affecting the database itself. This is normally a very quick process. On completion, you will see the message “Successfully updated Impact's database dictionary. It is recommended you perform an Integrity Check from the Database Administration form to verify the database against the dictionary”.