Performance hit with limit query on large dataset

thanks for the replies guys, the code I provided is not my actual code but a representation of what im doing. Ive edited my post to include the order direction.

@skunkbad, I know about this->db->query(). The idea was to use active record to include the inner join / select

@mwhitney, this looks a bit more promising. I set of down this path but had not noticed get_compiled_select(). Ill give this a go and report back.