Re: Catalog_xmin is not advanced when a logical slot is lost

On Mon, Nov 21, 2022 at 10:56 AM Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org>
wrote:

> On 2022-Nov-21, sirisha chamarthi wrote:
>
> > I have a old .partial file in the data directory to reproduce this.
>
> I don't think the .partial file is in itself important. But I think
> this whole thing is a distraction.

Yes, sorry for the confusion.

> I managed to reproduce it
> eventually, by messing with the slot and WAL at random, and my
> conclusion is that we shouldn't mess with this at all for this bugfix.
>

Agreed.

> Instead I'm going to do what Ashutosh mentioned at the start, which is
> to verify both the restart_lsn and the invalidated_at, when deciding
> whether to ignore the slot.
>

Sounds good to me. Thanks!

>
> It seems to me that there is a bigger mess here, considering that we use
> the effective_xmin in some places and the other xmin (the one that's
> saved to disk) in others. I have no patience for trying to disentangle
> that at this point, though.

> --
> Álvaro Herrera PostgreSQL Developer —
> https://www.EnterpriseDB.com/
> "Having your biases confirmed independently is how scientific progress is
> made, and hence made our great society what it is today" (Mary Gardiner)
>