Re: Pluggable database in 12C

From: Noons <>
Date: Fri, 19 Oct 2012 20:16:02 +1100
Message-ID: <k5r5oi$o4$>

ddf wrote,on my timestamp of 19/10/2012 1:08 AM:

> I agree that the single set of LGWR processes will be the Achiles' heel of
> the 'pluggable database' revolution. To be fair, though, MySQL got that idea
> from Sybase years before (the same place , I believe, Informix got it) so
> it's been around for a LONG, long time. As Noons mentioned SQL Server (and
> Sybase, if I remember correctly) have transaction logs for each database, not
> a single set for the entire server, so that contention between database
> transaction logging shouldn't happen.

It's not just the contention. In MSSQL I can easily restore a PDB from a backup and do a PITR without affecting any of the other PDBs. And of course I can back it up separately as well! I hope I can do that with 12c as well but I don't see exactly how at this stage. Early days though, so let's wait and see. I suspect we'll see a "re-synch" utility/function to provide such flexibility and other necessary global dictionary integrity.

> That Oracle couldn't think that far
> ahead ... well, I suppose the marketing department was getting a lot of
> grumpy email and feedback on the fact that 12c had been announced for quite a
> while but nothing was ever said to solidify WHEN it would be available.

Hmmm... Partly agreed. I rather think their R&D wasted too long pursuing the confusion idiocy and let their cash cow fall behind in features. But of course I'm a dinossaur dba 1.0, so what do I know of all those illuminated stratospheres? Oh hang on, I'm also a paying customer!
Aw foggedaboudit, that counts for exactly squat...

 > I
> would expect that in 12.2 the LGWR flaw will be corrected (once the early
> adopters find bucketloads of contention after they load up their containers
> with several fairly active databases each) as the hoi paloi will not stand
> for such an obvious and correctable performance problem (again, if Sybase,
> SQL Server and MySQL can prevent it why can't Oracle).

Like I said: let's wait and see. The latest info is that it'll be out somewhere mid 2013. I suspect that will be slightly delayed once it percolates up there are a couple of flies in the ointment.
I suspect the whole purpose of this early announcement is precisely to flush out such flies and address them before release. But rest assured those doing the flushing won't see a single atom of recognition of their support of the product and their willingness to help improve it!... Received on Fri Oct 19 2012 - 11:16:02 CEST

Original text of this message