> -----Ursprüngliche Nachricht----- > Von: Eduardo Morras [mailto:[EMAIL PROTECTED] > Gesendet: Freitag, 1. Dezember 2006 19:44 > An: sqlite-users@sqlite.org > Betreff: Re: [sqlite] for what reason :memory: is much slower than > /dev/shm/dummy.db > > > At 09:34 01/12/2006, you wrote: > >Hi there, > > > >we are on an challanging project with very high requirements > on performance. > >When doing some debugging we discover, that the sqlite > method for creating > >an memory-based database is much slower than using e.g > /dev/shm on linux or > >/tempfs on solaris. (We have measured an 20min performance > advantage for the > >/dev/shm style on a batch run which takes 70min with > :memory: and just 49min > >using /dev/shm. > >Because our project needs to be ported to windows - the > /dev/shm is not an > >option - because win2000 does not support any temporary > memory based file > >system. But beside that, we guess, that there will be a > possiblity to tune > >:memory: or we belief, that we to something wrong when using > :memory: (for > >example pragma page_size ...). > >Is there any body who can give us some advises to tune up > our :memory: > >database to become as fast as the /dev/shm alternativ? > > > >Thanks > >roland > > On our project we desisted to use :memory: databases, only a ram disk > file system. From time to time make a snapshot to hard disk or other > persistent medium. > > In windows i suppouse you can make a ram disk using malloc and copy > there your database file, set the pragma for temporary files to > memory and disable journaling. Make a new io routines access based on > windows, open/close, write/read etc... for access your memory malloc > ram disk. Again, from time to time stop reads/writes to database and > save it to disk. > > HTH > Hello Eduardo,
thank you for the hints given. Please can you tell me how to disable journaling? In our project it is not important to have the database persistent. We create the database, work with it, and destroy it within one batch run. So we dont have to save it to disk ;-). thank you so far roland > > -------------------------------------------------------------- > -------------------------------------------------------------- > --------------------------------------- > Scientists have shown that the moon is moving away at a tiny yet > measurable distance from the earth every year. > If you do the math, you can calculate that 85 million years ago the > moon was orbiting the earth at a distance of > about 35 feet from the earth's surface. This would explain the > death of the dinosaurs. The tallest ones, anyway. > > > -------------------------------------------------------------- > --------------- > To unsubscribe, send email to [EMAIL PROTECTED] > -------------------------------------------------------------- > --------------- > ----------------------------------------------------------------------------- To unsubscribe, send email to [EMAIL PROTECTED] -----------------------------------------------------------------------------
