Rails - find_each
An active record reloadtion does not automatically load all records into memory.
When we call #each, all records will be loaded into memory.
When we call #find_each, records will be loaded into memory in batches of the
given batch size.
So if our query returns a huge number of records, much memory will be used ->
server provides much resources –> Use find_each would be a great choice.
It’s like using ruby’s lazy enumerations #to_enum#lazy with #each_slice and
#each