What software should I use for manually drawing schema diagrams? [closed]

Question

Our application has a fairly large, sprawling DB design, with 175 tables. Most tables are used by one or two primary features, and I'd like to create several little "mini-schemas" to describe the structure of different parts of the system to new hires (without showing them the gigantic total schema which is, frankly, so big as to be useless).

Since these are already-extant tables, I need a tool which will allow me to enter completely custom names for fields and specify connections myself (since some of our foreign keys don't follow the standard naming pattern).

What's the best cheap or free tool for this?

Bonus points if it allows custom colors to be selected for diagram elements (i.e., tables), since this would allow me to create a reassembled version of the schema for discussion of how the major systems interact.

Answer 1

Well, it doesn't do custom colors, but MySQL Workbench is a free database modelling tool provided by MySQL.

You can even set it up to reverse engineer a full schema diagram just by having it connect to your database. You could take it from there and partition out what you needed into separate modelling diagrams.

Answer 2

For any kind of graph drawing I really find it hard to beat the utility of Graphviz; but it'd require you to learn a new (and I use "learn" loosely here) language called "dot". The language is incredibly simple, and there's plenty of templates around for using it to document schemas.

On a side note, there's an excellent schema mapping tool which can infer connections based on column names that may get you pretty close to what you need, it's called SchemaSpy.