Does SQlite (3.6.23.1 to be precise) perform any optimization when user function appears in the statement?
I defined custom function MY_FUNC(a TEXT, b TEXT) and bound it with sqlite3_create_function. Suppose, we have 2 tables: Tbl1(id1 INTEGER, id2 INTEGER, str TEXT) with 2 records Tbl2(id INTEGER, Tbl1_id INTEGER, str TEXT) with 5000 records Using query: SELECT Tbl2.id, MY_FUNC(Tbl1.str, Tbl2.str) FROM Tbl2 JOIN Tbl1 ON Tbl1.id1=Tbl2.Tbl1_id WHERE Tbl2.id>1000 AND Tbl1.id2=1 LIMIT 50 I hope MY_FUNC would be evaluated 50 times at most, but it appeared 10000. Using subquery does not do anything with the problem. Any suggestion on how to avoid 10000 evaluation of time-consuming function? _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
