On Mon, Nov 28, 2016 at 07:45:16PM +0000, Howard Chu wrote: > Nico Williams wrote: > >One of the problems with LMDB's locks is that readers need write > >permission to the lock file, IIRC :( but at least it's a separate file. > > We developed an alternate locking protocol for Postfix. It just uses > standard fcntl() locks.
Yeah, I'm aware. > http://www.postfix.org/lmdb_table.5.html > > Of course nothing comes for free - with this approach, writers don't block > readers, but readers block writers. That's the best you're going to get > without custom lock protocols like LMDB uses natively. TANSTAAFL, I know. A proper COW DB with coalesce-and-rename-into-place would need no locking of any kind for readers, at the price of needing more storage and more I/O to do the vacuuming. _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
