On Fri, Nov 11, 2011 at 8:06 PM, Petite Abeille <petite.abei...@gmail.com> wrote: >> No, "exists" in this case will change query plan significantly and >> performance can degrade drastically as a result. > > Why would that be?
How would you rewrite the query using exists? The only thing I have in mind is SELECT * FROM table2 WHERE exists ( SELECT 1 FROM table1 WHERE amount > 500 AND table1.rowid = table2.rowid) And this query will force SQLite to use the second query plan I talked about: scan full table2 and for each row search in table1 for rows with the same rowid and check if it has necessary amount. And this plan will very likely be slower. Pavel _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
