On 10/1/16, Heather, James (ELS-LON) <james.heat...@elsevier.com> wrote: > > This is odd. I had rather assumed it would be possible to speed up the > searching using those individual indexes... in fact I know it's possible, > because MySQL performs the same query very much faster when I add the > individual indexes. How MySQL differs from sqlite in terms of its optimiser, > I've no idea; but am I right that MySQL stands as an existence proof that > the individual indexes can be used to solve the problem efficiently?
You might get a satisfactory result using your 6 single-column indexes if you just run ANALYZE after creating the indexes. Probably this is what MySQL is doing (except that it runs the ANALYZE automatically as it creates the index so that you don't have to). Please try running ANALYZE and let us know what happens. A single three-column index will still be a better solution, though. -- D. Richard Hipp d...@sqlite.org _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
