I have an Oracle database. It has multiple schemas, and each schema has many tables.
Is there a way to generate a tree diagram or block diagram, such as this image, to visualize the database?

I would like this so I can understand the DB better.
I have an Oracle database. It has multiple schemas, and each schema has many tables.
Is there a way to generate a tree diagram or block diagram, such as this image, to visualize the database?

I would like this so I can understand the DB better.
If the database tables with references constraints that define the relationships, you can use tools like Toad to automatically create entity relationship diagrams (the fancy name for the image you reference). However, if there are not references constraints, you will have to create the diagrams manually.