On 7 Apr 2013, at 2:08pm, Baruch Burstein <bmburst...@gmail.com> wrote:
> If I issue a select statement with a ORDER BY clause and a LIMIT clause, > does SQLite do a full sort (assuming no index) and then return the first X > rows, or just a partial sort to get the first X sorted results? The ORDER BY clause does not know about the LIMIT clause. So even with a LIMIT 1 it doesn't know that all it needs to do is pick the lowest value and not bother sorting the rest. A limit clause just makes _step() return "I'm run out of result rows" sooner than normal. It's like doing _prepare() _step() _step() _finalize() stopping _step() after a few times, before you run out of results. So the LIMIT clause has no influence on any ORDER BY clause. Actually what you suggest is an interesting optimization. But I think it would introduce too much extra code to be appropriate for SQLite. Simon. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
