On Mon, Jun 8, 2020 at 12:09 PM Robert Haas <robertmhaas@gmail.com> wrote:
> I think the big overhead is that you log the old version of each row's
> primary key (or whatever the replica identity is) when performing an
> UPDATE or DELETE. So if you test it with integer keys probably it's
> not bad, and I suspect (though I haven't looked) that we don't do the
> extra logging when they key hasn't changed. But if you have wide text
> columns as keys and you update them a lot then things might not look
> so good. I think in the bad cases for this feature the overhead is
> vastly more than going from minimal to replica.
>
> As many people here probably know, I am in general skeptical of this
> kind of change. It's based on the premise that reconfiguring the
> system is either too hard for users to figure out, or too disruptive
> because they'll need a restart.
I completely agree with your analysis, and your conclusions.
--
Peter Geoghegan