[RFC] Switch on tdb2 API by default?

[simo]

On Thu, 2011-09-22 at 10:38 +0930, Rusty Russell wrote: 
> Hi all!
> 
>    The TDB2 code (ie. --enable-tdb2) runs in TDB1 mode by default now
> (there's a tdb_compat shim which inserts the TDB_VERSION1 flag unless
> the env var TDB_COMPAT_USE_TDB2 is set).
> 
>    So I'd like to make --enable-tdb2 the default now.  That way we can
> test the tdb2 API, and have a run-time flag to enable the tdb2 on-disk
> format for the brave.
> 
>    This lets us get rid of some compat cruft; for example, tdb2 handles
> multiple opens internally, so the various db_wrap codes wouldn't have
> to.  We can also add a tdb2 alloc attribute to (finally!) make tdb2 use
> talloc() for SAMBA.
> 
> I'm particularly interested in regressions if we turn this on.  For
> example, tdb2 functions return the negative error code, not -1: I think
> I got all the callers, but new ones may appear.
> 
> Thoughts?
> Rusty.

I'd like a more thought out transition. Distributions build TDB
standalone and this means it will probably require a so name bump and
relinking of all users. Also using an environment variable to change
format seem sort of dangerous to me. Wouldn't it be better to make it an
explicit option in the new tdb_open (assuming it is not already).

Simo.

-- 
Simo Sorce
Samba Team GPL Compliance Officer <simo at samba.org>
Principal Software Engineer at Red Hat, Inc. <simo at redhat.com>