[PATCH] GUID index for LDB

Andrew Bartlett abartlet at samba.org
Tue Sep 12 21:33:40 UTC 2017

On Tue, 2017-09-12 at 22:47 +0200, Volker Lendecke wrote:
> On Wed, Sep 13, 2017 at 06:46:28AM +1200, Andrew Bartlett wrote:
> > Sorry, I should have given some context to that.  I'm being asked
> > by
> > clients to evaluate LMDB as a backend choice because the apparent
> > DB
> > size (2.4GB) of a large AD domain (100k user, or for example less
> > users
> > and more jpegPhoto) is too close to comfort to the 4GB limit of
> > TDB.  
> What's the real content of the db? "tdbtool <db> info" would be
> great.

I attached that earlier in the thread at metze's request.  Feel free to
take a look. 

> 2.4GB is the indicated file size, how much data is actually in there?
> But probably we could optimize transactions to waste less disk space.

We could, but as I say, as soon as you start loading in staff photos (a
reasonable use case), even at 10,000 users 4k per photo would fill it. 

> Also, if ldb adopted dbwrap, it might be simpler to shard across more
> than one tdb.
> Also, with tdb now having solved many of the problems that tdb2 was
> set out to solve with a completely new implementation, just doing
> 8-byte offsets should be a lot easier than a complete rewrite.


Anyway, we are off on a tangent.  For now I'm just trying to get the
GUID index in :-)


Andrew Bartlett

Andrew Bartlett
Authentication Developer, Samba Team         https://samba.org
Samba Development and Support, Catalyst IT   

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