RE: Disable WAL logging to speed up data loading

Hi

Thank you everyone
On Thursday, January 14, 2021 9:27 AM Tsunakawa, Takayuki/綱川 貴之 <tsunakawa(dot)takay(at)fujitsu(dot)com> wrote:
> From: Kyotaro Horiguchi <horikyota(dot)ntt(at)gmail(dot)com>
> > > XLogSetRecordFlags(XLOG_MARK_UNIMPORTANT |
> > XLOG_MARK_ESSENTIAL);
> > > XLogRegisterData((char *) &dummy, sizeof(dummy));
> > >
> > > (Here's a word play - unimportant but essential, what's that?)
> >
> > Hmm. Food may not be important to someone but it is essential for
> > survival. I think this is somethig like that :p
>
> Ah, that's a good answer. I know a person around me who enjoys drinking
> alcohol but doesn't enjoy eating - he says he doesn't care about taste of food.
> So food is unimportant but nutrition is essential for him.
>
>
> > Unfortunately, I prefer the latter as it is simple because it is in a
> > hot path. As I think I mentioned upthread, I think the xlog stuff
> > should refrain from being conscious of things deeper than RMger-ID
> > level. One of other reasons is that generally the issuer site is the
> > authoritative about the importance and essentiality of a record being
> > issued. And I don't think it's very good to do the same thing in
> > different ways at the same time. Fortunately each type of the recrods
> > has only few issuer places.
>
> Agreed.
>
>
> > By the way, I noticed that pg_switch_wal() silently skips its task.
> > Desn't it need to give any sort of ERROR?
>
> Osumi-san, can you check this? (I thought we were aware of this according to
> Fujii-san's comment.)
I updated my patch to take in those feedbacks !
Have a look at the latest patch.

Best Regards,
Takamichi Osumi