..representation of a decent sized real world network.. On Tue, Mar 22, 2011 at 10:59 AM, Bart Smissaert <[email protected]>wrote:
> > through a version of dijkstra's routing algorithm > > Just out of interest, what data is this working on? > > RBS > > On Tue, Mar 22, 2011 at 7:25 AM, Amit Chaudhuri > <[email protected]> wrote: > > [Not at all expert in sqlite but here's a practical example of speed up > > using ":memory:" and perhaps a slightly different strategy for getting at > > the persistent data.] > > > > I use sqlite3 with Qt4 / C++ for an application which reads in an > undirected > > graph and then chunks through a version of dijkstra's routing algorithm. > A > > colleague runs this on his machine and it takes all night on a large > network > > running on a database on disk. On my own machine which is more powerful > it > > probably runs a lot faster but still takes a couple of hours plus. > Changing > > to an in memory database, reading data in and processing in memory brings > > the run time down to a couple of minutes. So yes - running in memory can > be > > much quicker. At the end of the run I attach an on disk database and > copy > > out the tables I need to save using "create table select...." . > > > > A > > > > On Mon, Mar 21, 2011 at 1:13 PM, Simon Friis <[email protected]> wrote: > > > >> I know how to create a database that exists only in memory by using > >> the :memory: filename. This however, creates a new database every time > >> and it can not be saved. > >> > >> Is is possible to make SQLite load a database file into memory and > >> then save it back to the file again when the connection to the > >> database is closed? > >> > >> Would it improve speed? > >> > >> - paldepind > >> _______________________________________________ > >> sqlite-users mailing list > >> [email protected] > >> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > >> > > _______________________________________________ > > sqlite-users mailing list > > [email protected] > > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > > _______________________________________________ > sqlite-users mailing list > [email protected] > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list [email protected] http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
