Re: [Proposal] Fully WAL logged CREATE DATABASE - No Checkpoints

On Mon, Mar 28, 2022 at 2:18 AM Dilip Kumar <dilipbalaut(at)gmail(dot)com> wrote:
> > I have put the similar logic for relmap_update WAL replay as well,
>
> There was some mistake in the last patch, basically, for relmap update
> also I have checked the missing tablespace directory but I should have
> checked the missing database directory so I have fixed that.
>
> > Now, is it possible to get the FPI without smgr_create wal in other
> > cases? If it is then that problem is orthogonal to this path, but
> > anyway I could not find any such scenario.
>
> I have digged further into it, tried manually removing the directory
> before XLOG_FPI, but I noticed that during FPI also
> XLogReadBufferExtended() take cares of creating the missing files
> using smgrcreate() and that intern take care of missing directory
> creation so I don't think we have any problem here.

I don't understand whether XLOG_RELMAP_UPDATE should be just doing
smgrcreate() as we would for most WAL records or whether it should be
adopting the new system introduced by
49d9cfc68bf4e0d32a948fe72d5a0ef7f464944e. I wrote about this concern
over here:

http://postgr.es/m/CA+TgmoYcUPL+WOJL2ZzhH=zmrhj0iOQ=iCFM0SuYqBbqZEamEg@mail.gmail.com

But apart from that question your adaptations here look reasonable to me.

--
Robert Haas
EDB: http://www.enterprisedb.com