SchemaSpy

SchemaSpy is a very useful tool for database Administrators and Developers. The basic purpose of SchemaSpy is to auto-generate schema for any database. But it's evolved in a great tool that can give us so much valuable information about any database. The case in question is that of a complex database consisting of more than 30 tables with some tables having fields in excess of 50 and complex links.

I won't go into details of everything here but rather I'll outline major points. After successfully running SchemaSpy on a database you are presented with an output of number of HTML files in the designated folder on your PC. The index.html file is the starting point for this output. After opening it you can see following tabs.
 

And that's a lot of information that you get about the database.

The first tab - tables - lists all the tables, next one displays a relationship diagram, next lists Utility tables and details for them, the next one does constraints, after that it even shows anomalies that can affect the integrity of your data, then's one that lists all columns in your database and the last tab takes you to donate link.

Overall you can see that SchemaSpy is a powerful tool for DBA/Developers.

To use it, you need couple of things:
1. The JRE - since Schema Spy is written in Java.
2. GraphViz - Schema Spy uses graphviz to create the relationship diagram seen in second tab.