Re: Disable WAL logging to speed up data loading

Sorry for the slippery brain...

At Fri, 02 Oct 2020 13:38:22 +0900 (JST), Kyotaro Horiguchi <horikyota(dot)ntt(at)gmail(dot)com> wrote in
> At Fri, 2 Oct 2020 10:56:21 +0900, Fujii Masao <masao(dot)fujii(at)oss(dot)nttdata(dot)com> wrote in
> >
> > On 2020/10/02 10:06, Kyotaro Horiguchi wrote:
> > > 1. Flip BM_PERMANENT of active buffers
> > > 2. adding/removing init fork
> > > 3. sync files,
> > > 4. Flip pg_class.relpersistence.
> > > It always skips table copy in the SET UNLOGGED case,
> >
> > Even in wal_level != minimal?
> > What happens in the standby side when SET UNLOGGED is executed without
> > the table rewrite in the primary? The table data should be truncated
> > in the standby?
>
> A table turned into unlogged on the primary is also turned into
> unlogged on the standby and it is inaccessible on the standby.

> Maybe the storage is dropped on both patched and unpatched versoins.

Maybe the storage dropped on unpatched and left alone on patched.

> After the table is again turned into logged, the content is
> transferred via WAL records generated from the insertions into the new
> storage and it rebuilds the same storage on the standby on both
> patched and unpatched.

regards.

--
Kyotaro Horiguchi
NTT Open Source Software Center