On 4/03/2009 2:12 PM, Peng Huang wrote: > Hi Igor Tandetnik, > > Thanks for your quick reply. > > Your solution works. But in some cases, each y%d may has two or three > choices. So the SQL will become very complex, we need ( 2 * 2 * 2 * 2) sub > where statements. Does SQLite have some build-in features to optimize those > kinds of SQL statements? Or do you have other suggestions to optimize the > database of SQL statements? > > For example: > "SELECT * FROM py_phrase WHERE ylen = ? and (y0 = ? or y0 = ?) and (y1 = ? > or y1 =? ) and (y2 = ? or y2 = ?) and (y3 = ? or y3 = ? or y3 = ?) ORDERY BY > user_freq DESC, freq DESC" >
(y3 = ? or y3 = ? or y3 = ?) is *logically* equivalent to (y3 IN (?, ?, ?)) Does it run at the same speed? _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
