> I would be interested to know if handing a sequential file over the > same NFS connection shows the same behaviour. This would use > fread() which should trigger any caching that the operating system > and file system implement for that type of connection. You could > test this using a text editor and a very long text file.
Already tested that and as expected, pages remain in the cache. I basically did cat /nfs/machine/location/file.txt (a file of around 5GB) 1> /tmp/foobar. I can see using both xosview and vmtouch that the pages aren't evicted - until a process needs RAM of course. In fact, if I 'dd if=<the DB file>' over NFS then the pages are cached as expected. It is only when SQLite itself opens the file are the pages immediately evicted. Jim > I haven't looked at the code for SQLite. As far as I know, even > though you can tell SQLite that /you/ aren't going to make changes > to the file, there's no way to tell it that nobody else is going to > make changes between your SELECT commands. Consequently there's no > way to force it to use the cache. > > Simon. > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > -- Jim Vanns Senior Software Developer Framestore _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
