Re: Antw: Re: LMDB database size

[Howard Chu <hyc@symas.com>]

Ulrich Windl wrote:
> > > > Howard Chu <hyc@symas.com> schrieb am 25.01.2014 um 19:07 in Nachricht
> <52E3FD6E.9070906@symas.com>:
> > Markus Doppelbauer wrote:
> > > Hello,
> > > We are using BerkeleyDB since a decade - but we are searching for something
> > > more lightweight. LMDB is what we are looking for ...  ^^
> > > The small code  and the benchmark-results are very impressive!
> > > A question: We have a server with 4 GB RAM. One of the BerkeleyDB-files has
> > > about 20 GB.This particular database is a kind of archive - hardly read and
> > hardly
> > > written (maybe once per minute).
> > > Is it possible to "mmap()" a 20 GB database into the RAM?
> >
> > Yes.
> >
> > > If yes, will the server
> > > start "swapping"?
> >
> > No.
>
> This is only true (AFAIK)

You've already demonstrated multiple times that "as far as you know" is not 
far at all.

> if the applications uses huge pages or memory
locking. In other cases it depends on the OS and the other applications.
> In general mmap files "swap" onto themselves, and you would not call it
"swapping" in the usual sense...

Thus, the answer is "No", as I already said, and you have added no value to 
the discussion.
> Ulrich



--
  -- Howard Chu
  CTO, Symas Corp.           http://www.symas.com
  Director, Highland Sun     http://highlandsun.com/hyc/
  Chief Architect, OpenLDAP  http://www.openldap.org/project/