ruby on rails - What the difference between mysql and mysql2 gem

Question

I used to work with the mysql gem, but often nowadays I hear about the mysql2 gem. Also, it is included in the Gemfile by default in Rails 3.0.x.

What is the difference and advantages of using the mysql2 gem?

Answer 1

Here's a quote from the mysql2 gem page:

Yeah… but why?

Someone: Dude, the Mysql gem works fiiiiiine.

Me: It sure does, but it only hands you nil and strings for field values. Leaving you to convert them into proper Ruby types in Ruby-land - which is slow as balls.

Someone: OK fine, but do_mysql can already give me back values with Ruby objects mapped to MySQL types.

Me: Yep, but its API is considerably more complex and can be ~2x slower.