samba - May 2007 - TDB functionality document

Hi,

Does someone know a document which explains the TDB structure.
functionalites, and format of the TDB files etc.

I need to understand why some of the TDBs like messages.tdb, unexpected.tdb,
brlock if not read_only, locking.tdb, session.tdb, wins.tdb are called with
TDB_CLEAR_IF_FIRST tdb flags.

Why some TDBs are opend with O_RDWR|O_CREAT flags viz. gencache.tdb,
group_mapping.tdb, account_policy.tdb, share_info.tdb, secrets.tdb.
schannel_store.tdb etc. etc.

why registry.tdb is uniquely been tried to open with O_RDWR flag and if
fails then tried with O_RDWR|O_CREAT flag.

and such internal details of the TDBs.
>From the code study I am not getting the complete picture of this component.
Can any one help me by sharing any information available with them related
to this.

Thanks in advance.
regards
Aravind

On Wed, 2007-05-09 at 00:05 +0530, Aravinda Guzzar
wrote:
> Hi,
> 
> Does someone know a document which explains the TDB structure.
> functionalites, and format of the TDB files etc.
> 
> I need to understand why some of the TDBs like messages.tdb,
unexpected.tdb,
> brlock if not read_only, locking.tdb, session.tdb, wins.tdb are called with
> TDB_CLEAR_IF_FIRST tdb flags.
This flag is used to clean up the db contents on startup. If the process
is the first consumer it will clean out the TDB, otherwise not.

This is used because these are temporary TDBs, it make no sense to keep
the content when the consumers are restarted from scratch.
> Why some TDBs are opend with O_RDWR|O_CREAT flags viz. gencache.tdb,
> group_mapping.tdb, account_policy.tdb, share_info.tdb, secrets.tdb.
> schannel_store.tdb etc. etc.
These are permanent TDBs, you need to create them only if they do not
exists, otherwise just open RW.
> why registry.tdb is uniquely been tried to open with O_RDWR flag and if
> fails then tried with O_RDWR|O_CREAT flag.
no idea
> and such internal details of the TDBs.
I think the best we have right now is in tdb/docs/README

Feel free to post wuestions but you will have better chances to reach
the developers (ie people that understand TDB internals) by posting at
samba-technical@samba.org

Simo.

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

Hi Simo,

Thanks for the information, the information was indeed very helpful.

I have asked this questin in the samba-technical lists too.

thanks again
Aravind