On 21 Jan 2012, at 5:49pm, Ryan Johnson wrote: > In one case the optimizer seems to make a different decision depending on > which order I write the join in; in the other case, the join ordering chosen > is bad and compounded by an expensive subquery not being materialized into a > transient table as it should be. > > For the first issue, consider the following query: > > select count(*) from orders O, Customer C where C.custkey=O.custkey and > C.name like '%115';
I see no JOIN. I see a WHERE. And it's not clear to me what you're trying to count: orders or customers. I don't know if SQLite can work it out so try one of the following: select count(*) from orders O JOIN Customer C ON C.custkey=O.custkey WHERE C.name like '%115'; select count(*) from Customer C JOIN orders O ON C.custkey=O.custkey WHERE C.name like '%115'; Simon. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
