"ORDER BY" without large table scans and filesort

[Marco van Herwaarden]

[sql]select * from post where postid = (select max(postid) from post)[/sql]But i think this will only work for MySQL 4.1 and up.

Otherwise create 2 queries: 1 to get max postid, and 1 to retrieve the row.

Ohh my example is for post table, but should be the same for thread.

Also please notice that you should check with a fully loaded table, since the optimizer might decide that if there are only a few rows, it is more efficient to use a full table scan then to use the index.