Thanks! I've posted that information in the bug. Cheers,
Shawn On Thu, May 22, 2008 at 4:09 PM, D. Richard Hipp <[EMAIL PROTECTED]> wrote: > > On May 22, 2008, at 9:40 AM, Shawn Wilsher wrote: > >> It was mentioned in the bug that opening the file with the O_SYNC flag >> would no longer require fsyncs. Has this been looked into before by >> sqlite? >> > > I have a prepared a version of SQLite that uses O_SYNC on the main > database file and its journal and never calls fsync(). I ran this on > SuSE 10.1 x86 and found that preformance was roughly half of what we > got using fsync() (with synchronous=FULL). Here are the numbers: > > O_SYNC: > > real 13m6.918s > user 0m14.693s > sys 0m22.329s > > fsync: > > real 7m5.159s > user 0m14.745s > sys 0m11.049s > > But versions were compiled with -Os. Gcc version 4.1.0. > > Of course, your mileage may vary, but based on the magnitude of the > difference seen above, I'm thinking that O_SYNC is probably a bad idea. > > As a point of comparison, the same code compiled with - > DSQLITE_NO_SYNC=1 is between 40 and 70 times faster: > > real 0m10.479s > user 0m6.736s > sys 0m3.732s > > Oh, what a difference a disk cache makes..... > > D. Richard Hipp > [EMAIL PROTECTED] > > > > _______________________________________________ > 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
