def each_row_batch(options={}, &block)
        options = {:connection => self.connection}.merge(options)
        all.each_row_batch(options, &block)
      end
Public: Executes the query, yielding an array of up to block_size rows
where each row is a hash to the given block.

Parameters: same as each_row

Example:
Post.each_row_batch { |batch| Post.process_batch(batch) }

Returns the number of rows yielded to the block