I emailed sqlitemanager support re the manage/sql tab performance difference. Mystery solved by the reply:
"In the Manage panel when you see SELECT * FROM table the real query executed is SELECT rowid FROM table and then a SELECT * FROM table WHERE rowid=N is execute for each visible row of the listbox. In the SQL panel query executed is just what you type" On Mar 6, 2012 5:47 PM, "Pete" <p...@mollysrevenge.com> wrote: > I just noticed that the same vendor that makes SQLiteManager also makes an > SQLite server package (cubeSQL) that does implement MVCC. But you're > right, it's definitely not there in standard SQLite. An SQLite server > sounds interesting though. > Pete > > On Tue, Mar 6, 2012 at 11:35 AM, Bernard Devlin <bdrun...@gmail.com>wrote: > >> I notice from things discussed on the Valentina list that they >> recommend using API methods rather than SQL calls, because the former >> will be faster due to less overhead. So these different ways of >> interacting with a sqlite database might well represent an application >> using the sqlite API. >> >> Although when I use the Valentina VStudio SQL interface I will still >> see results being returned in 25 ms, compared to 500 ms going through >> sql yoga > revdb > v4rev sql > valentina. This is doing a "select *" >> from a table with 22k rows (10mb in size). That's not to say that I'm >> outraged at 500ms. There are other steps one can take to make an >> interface responsive at these timescales. >> >> The Valentina guys are pretty used to comparing Livecode with the >> other platforms for which they provide Valentina. On 19/12/2010 >> Ruslan had this to say about Livecode: >> >> "REALbasic - as I remember -- was very fast, near to C code...so it >> gives e.g. 5% overhead to pure C engine... Revolution and Director >> give me x4-x10 overhead I think....Revolution because all params are >> packed to strings ... Director because quite complex SDK similar to MS >> COM ..." This conclusion by Ruslan appears to be only in the >> discussion of calling the Valentina API, therefore one would expect >> that adding other layers (sql, revdb, etc.) one would see other layers >> adding their own torpor to the action. >> >> Does using explict transation control make any difference with sqlite? >> It shouldn't matter in a case where the data is only being read. I >> know on MVCC databases this is still a factor if one has a cursor >> containing the read data, as such data might still be altered from the >> cursor and the currency control of the MVCC requires a handle on such >> data to be able to maintain consistency. I can't see that it would >> apply to sqlite, and this site confirms that sqlite does not implement >> MVCC: http://www.sqliteconcepts.org/SI_index.html >> >> Bernard >> >> On Tue, Mar 6, 2012 at 5:15 PM, Pete <p...@mollysrevenge.com> wrote: >> > I got the same results on the movies database and even more pronounced >> > differences on a table in one of my own databases with ~48k records in >> it: >> > SQL tab 0.519secs, Manage tab 0.045 secs, more than a 10-fold >> difference! >> > Just a straight SELECT * in each case. >> > Pete >> >> _______________________________________________ >> use-livecode mailing list >> use-livecode@lists.runrev.com >> Please visit this url to subscribe, unsubscribe and manage your >> subscription preferences: >> http://lists.runrev.com/mailman/listinfo/use-livecode >> >> > > > -- > Pete > Molly's Revenge <http://www.mollysrevenge.com> > > > _______________________________________________ use-livecode mailing list use-livecode@lists.runrev.com Please visit this url to subscribe, unsubscribe and manage your subscription preferences: http://lists.runrev.com/mailman/listinfo/use-livecode
