CheckMyGM and CheckMyC2 can be run in Microsoft SQL Management Studio to check your GoldMine database and SQL server for common problems.
CheckMyGM.SQL - Checks for almost everything I could think of on a SQL server with a GoldMine database. Runs only on a database with both CONTACT files and GMBASE files.
CheckMyC2.SQL - Compares structure of what's defined in CONTUDEF and what currently exists in CONTACT2, and lets you know if there are any potential issues. Run it on a GoldMine database before you try to rebuild your CONTACT2 table to see if you should expect problems.
Naturally you should use these at your own risk. As they sit here, they don't "DO" anything. Just feed you back information. But they may suggest actions for you to take that may irretrievably damage your data. Use at your own risk.