On 11/1/05, Kevin Burton wrote: > MyISAM has a cool feature where it keeps track of the internal row > count so that > > SELECT COUNT(*) FROM FOO executes in constant time. Usually 1ms or so. > > The same query on INNODB is O(logN) since it uses the btree to > satisfy the query.
Are you sure? Finding a single record using an index may be O(logN), but wouldn't reading all of the index be O(N)? Jochem