find_in_batches vs limit

Is the :limit option in the regular find call effectively same as
doing find_in_batches? or does doing something like the following
loads "all" of the record and then returns only 5?

find(:all, :conditions => ['age > ?', age], :limit => 5)

It will only find 5 rows.

By the way you could easily have found this by looking at the docs for
find, or by trying it and looking in the log to see the SQL generated.

Colin