ldb speed

[simo]

On Mon, 2006-10-30 at 20:50 +1100, tridge at samba.org wrote:
> Simo,
> 
>  > Honestly, to make things easy we should store by GUID, because otherwise
>  > in handling renames you need a global lock and traverse each object to
>  > make sure there aren't references to the renamed object.
>  > Actually we do not check anything but sooner or later we need.
> 
> That would have horrible performance for our most common cases.
> 
>  > At the same time storing by DN is a big performance advantage. So in the
>  > end I think that being able to have 2 keys for the same record could be
>  > the best way (GUID and DN) so that references will be stored by GUID
>  > (and searches for the GUID will be equally fast) but all other
>  > operations will use the normalized DN as key.
> 
> no, having 2 keys for every record is a terrible idea. It means that
> every add/delete has to update at minimum two things, where we
> currently update one.

If this is made inside ldb_tdb I think we can make it fats enough.
Or we decide to store by GUID only when told, so that for local LDBs we
don't incur into this penalty.

> Renames are _rare_. It doesn't matter if they are hard to code, as
> long as they are possible to code (and it is certainly possible!).

Well, consider a person that drags 100 users from an OU to another.
And consider updating 5000 groups 100 times ...

Simo.

-- 
Simo Sorce
Samba Team GPL Compliance Officer
email: idra at samba.org
http://samba.org