On 11/03/2016 02:13 PM, sanhua.zh wrote:
I notice that SQLite may not call msync for mmap. Instead, it calls the fsync.
As my search, fsync does not imply the msync. See
this,https://groups.google.com/forum/#!topic/comp.unix.programmer/pIiaQ6CUKjU
So, is it necessary call a msync for SQLite?
Probably not in the default configuration, at any rate.
SQLite mmap-mode only works if the system has a unified page-cache.
Which is why it is disabled on some platforms (OpenBSD and others IIRC).
Also, unless SQLITE_MMAP_READWRITE is defined at compile time, SQLite
uses write() calls to modify to the db file, even though it reads the
file by memory mapping it.
Dan.
_______________________________________________
sqlite-users mailing list
sqlite-users@mailinglists.sqlite.org
http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
