On Wed, Feb 9, 2011 at 5:25 PM, Simon Slavin <slav...@bigfraud.org> wrote:
> > On 9 Feb 2011, at 7:32pm, Black, Michael (IS) wrote: > > > Didn't we just determine a couple of days ago that triggers were > performance killers? > > > > That's one reason I want to avoid those. > > Okay, then since your program knows the logic of how that table will be > used, it can do it for itself. Just do two INSERTS. > > Alternatively, if your language is capable of it, simply well-order the two > personIDs, so that the one in one column is always smaller than the one in > the other column. Then change your SELECT logic so that it returns the > UNION of SELECTing on both columns. > > One system speeds up the INSERTs, the other speeds up the SELECTs. It > depends which is the more important to you. > I assumed you could generate k in a procedural language outside of SQL, but if you want to do this purely in SQL, I think you can just say: create table t(k int primary key) insert into t values (min(?,?)<<32 | max(?,?)) and bind i,j,i,j to the parameters. For the select, same thing: select * from t where k=min(?,?)<<32 | max(?,?) and bind i,j,i,j I don't see the need to do 2 selects or 2 inserts, but maybe I'm not understanding something. Jim --- http://www.hashbackup.com _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
