Re: Online enabling of checksums

On Thu, Feb 22, 2018 at 4:47 PM, Andrey Borodin <x4mmm(at)yandex-team(dot)ru>
wrote:

> Hello, Magnus, Peter!
>
> I'm excited that this feature emerged, thanks for the patch. Hope it will
> help to fix some mistakes made during initdb long time ago...
>
> 22 февр. 2018 г., в 18:22, Peter Eisentraut <peter(dot)eisentraut(at)2ndquadrant(dot)
> com> написал(а):
>
> On 2/21/18 15:53, Magnus Hagander wrote:
>
> *Two new functions are added, pg_enable_data_checksums() and
> pg_disable_data_checksums(). The disable one is easy -- it just changes
> to disable. The enable one will change the state to inprogress, and then
> start a background worker (the “checksumhelper launcher”). This worker
> in turn will start one sub-worker (“checksumhelper worker”) in each
> database (currently all done sequentially).*
>
>
> This is at least the fourth version of the pattern launcher plus worker
> background workers. I wonder whether we can do something to make this
> easier and less repetitive. Not in this patch, of course.
>
>
> Peter, can I ask for some pointers in searching for previous versions?
> I want to review patch this patch and some code comparision could be
> handy....
>
> So far I've found only this [0,1] (without code) and threads mentioned by
> Magnus [2,3]
>
> Or do you mean extracting "worker+lancher" for reuse for other purposes?
>
>
I'm pretty sure Peter means the second. Which could be interesting, but as
he says, not the topic for this patch.

I'm not entirely sure which the others ones are. Auto-Vacuum obviously is
one, which doesn't use the worker infrastructure. But I'm not sure which
the others are referring to?

--
Magnus Hagander
Me: https://www.hagander.net/ <http://www.hagander.net/>
Work: https://www.redpill-linpro.com/ <http://www.redpill-linpro.com/>