which database is better for moodle?
Well...all you gurus?
Which is it?
Which is it?
I suspect you want to look at the Databases forum -- not here ;) Searching the forums also yields good answers to your question.
If you are new to databases, use MySQL because it's easier to get started with.
And if you have database experience with high-end or ACID databases... use Postgres 
Howard, does that mean I know what I'm doing???
Let's put it this way - If you say you do, then I believe you!! 