Re: POC: Cleaning up orphaned files using undo logs

On Wed, Jul 17, 2019 at 9:27 AM Thomas Munro <thomas.munro@gmail.com> wrote:
>
> On Wed, Jul 17, 2019 at 3:44 PM Dilip Kumar <dilipbalaut@gmail.com> wrote:
> > Right, actually I got that point.  But, I was thinking that we are
> > wasting one logno from undo log addressing space no?.  Instead, if we
> > can keep it attached to the slot and somehow manage to add to the free
> > list then the same logno can be used by someone else?
>
> We can never reuse log numbers.  UndoRecPtr values containing that log
> number could exist in permanent storage anywhere (zheap, zedstore etc)
> and must appear to be discarded forever if anyone asks.

Yeah right.  I knew that we can not reuse UndoRecPtr but forget to
think that if we reuse logno then it is same as reusing UndoRecPtr.
Sorry for the noise.

-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com