On Wed, May 14, 2008 at 2:09 PM, D. Richard Hipp <[EMAIL PROTECTED]> wrote:
> > On May 14, 2008, at 3:58 PM, Peter K. Stys wrote: > > > I'm curious, when you say performance enhancements, does that include > > improved R/W performance to/from remote volumes on OS X, which > > presently > > suffer serious (20-fold) speed issues. I had a recent post on this. > > If not, will 3.6.0 address this? > > > > Performance on a remote volume is about 20x slower because the raw I/O > capability of a network disk drive is about about 1/20th of a local > disk drive. There isn't anything much SQLite can do about that. > Dear Richard, I would disagree with this, unless I misunderstand. File copies (from the Finder under OS X) to/from our Xserve run at about 50 MBytes/s or about 50% of theoretical max on our Gbit LAN, whereas reading the records from the same file via SQLite is 20-25x slower (≈2MB/sec at best, terrible performance). So there is plenty of raw I/O bandwidth across the LAN and network drive, but for some reason SQLite access to its remote files is extremely slow (to be clear: these are single users accessing single files). In contrast SQLite R/W to local files runs at about 60% of raw binary file access on a local volume, very acceptable (≈35MB/s vs. 60-70MB/sec). So I don't understand why the huge performance hit (compared to other network file access like Finder copies, not comparing remote vs. local) when accessing remote SQLite files? I could understand some slowdown because of extra overhead with network operations, but 20-fold? Peter. -- --------------------------------------------- Peter K. Stys, MD Dept. of Clinical Neurosciences Hotchkiss Brain Institute University of Calgary tel (403) 210-8646 --------------------------------------------- _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
