Re: Cancel autovacuum conflicting with DROP TABLE

Alvaro Herrera <alvherre(at)commandprompt(dot)com> wrote:

> 1. changing SIGINT so that it cancels the current table instead of
> shutting down the entire worker.
>
> 2. changing DROP TABLE and TRUNCATE so that they cancel an autovac
> worker by sending SIGINT.

Quite so.

> 3. change the interrupt code so that autovac workers are terminated with
> ERROR instead of FATAL, knowing that the final outcome is the same. If
> I'm not mistaken the only point of the change is to be able to change
> the error message, is that correct?

Yes, I used ERROR instead of FATAL just for changing the message.
In addition, the actual message level will be LOG, instead of FATAL.

> I don't feel very much comfortable with the patch (3). I would prefer
> that we keep errcode FATAL and select a different error message in
> ProcessInterrupts instead. I don't see the point in complicating the
> sigjmp target without need.

My first patch did so and I changed it in the second patch because
I feel the FATAL entry in syslog is too obtrusive; Internal termination
of autovacuum workers in this way is ignorable for normal users.
However, I'm sure that my complaint is not so important. Please don't
apply thie part of the patch if you don't like it.

> I agree with the (2) change.
>
> The change in (1) I don't feel comfortable with commenting. It seems
> strange to me, and although it seems like it would be safe, I cannot
> help having a strange feeling about it. I'll try to digest it a bit
> more.

Thanks. I forgot to adjust comments in the code, sorry.

Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center