Re: Online enabling of checksums

Hi!

> 19 марта 2018 г., в 11:27, Heikki Linnakangas <hlinnaka@iki.fi> написал(а):
>
> Is there no way to stop the checksum helper once it's started? That seems rather user-unfriendly. I can imagine it
beinga pretty common mistake to call pg_enable_data_checksums() on a 10 TB cluster, only to realize that you forgot to
setthe cost limit, and that it's hurting queries too much. At that point, you want to abort. 
I've tried to pg_cancel_backend() and it worked.
But only if I cancel "checksum helper launcher" and then "checksum helper worker". If I cancel helper first - it spawns
new.

Magnus, Daniel, is it safe to cancel worker or launcher?

BTW, I have some questions on pg_verify_chechsums.
It does not check catalog version. It it true that it will work for any?
Also, pg_verify_chechsums will stop on short reads. But we do not stop on wrong checksum, may be we should not stop on
shortreads either? 

I agree with all of Heikki's comments.

Besides these I have no other questions, patch looks good.

Best regards, Andrey Borodin.