> Unfortunately I can't use such design because in this case I will not > able to find in the database such data as I need
Yes, you will be able to find information you need. You can store your data like this: time | val_num | value | --------|-----------|-----------| [time_1] 1 [value_1.1] [time_1] 2 [value_2.1] ... [time_1] XXXX [value_XXXX.1] [time_2] 1 [value_1.2] [time_2] 2 [value_2.2] ... [time_2] XXXX [value_XXXX.2] [time_3] 1 [value_1.3] [time_3] 2 [value_2.3] ... [time_3] XXXX [value_XXXX.3] Then your select will look like this: SELECT ... FROM table_name t1, table_name t2, table_name t456, table_name t654 WHERE t1.time > 1000 AND t1.time < 1500 AND t1.time = t2.time AND t1.time = t456.time AND t1.time = t654.time AND t1.val_num = 1 AND t2.val_num = 2 AND t456.val_num = 456 AND t654.val_num = 654 AND (t1.value > t2.value + 3 OR t456.value != t654.value) It looks like it's more complicated but I believe it will work faster than your multi-column approach. Pavel On Sat, Sep 19, 2009 at 1:18 AM, Konishchev Dmitry <konishc...@gmail.com> wrote: >> It'll work, but SQLite does not use a balanced tree to store the >> columns for a particular record. So if you're seeking the 700th >> column of a particular row, it has to look through 699 others before >> it gets to it. Unless you always handle all the columns of a row >> together, it'll be slow. > Thanks for this information, it is helpful for me. > >> Because of speed, and the difficulty of correctly handling such a long >> INSERT line, it's usually better to break this down into properties. >> So instead of >> >> ID prop1 prop2 prop3 prop4 >> -- ----- ----- ----- ----- >> 1 rec1p1 rec1p2 rec1p3 rec1p4 >> 2 rec2p1 rec2p2 rec2p3 rec1p4 >> >> Do >> >> ID propNumber propValue >> -- ---------- --------- >> 1 1 rec1p1 >> 1 2 rec1p2 >> 1 3 rec1p3 >> 1 4 rec1p4 >> 2 1 rec2p1 >> 2 2 rec2p2 >> 2 3 rec2p3 >> 2 4 rec2p4 > Unfortunately I can't use such design because in this case I will not > able to find in the database such data as I need (I described problems > with which I faced in > http://www.mail-archive.com/sqlite-users@sqlite.org/msg46229.html). > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
