Re: Time delayed LR (WAS Re: logical replication restrictions)

Hi,

On 2023-02-11 05:44:47 +0000, Takamichi Osumi (Fujitsu) wrote:
> On Saturday, February 11, 2023 11:10 AM Andres Freund <andres@anarazel.de> wrote:
> > Has there been any discussion about whether this is actually best
> > implemented on the client side? You could alternatively implement it on the
> > sender.
> > 
> > That'd have quite a few advantages, I think - you e.g. wouldn't remove the
> > ability to *receive* and send feedback messages.  We'd not end up filling up
> > the network buffer with data that we'll not process anytime soon.
> Thanks for your comments !
> 
> We have discussed about the publisher side idea around here [1]
> but, we chose the current direction. Kindly have a look at the discussion.
> 
> If we apply the delay on the publisher, then
> it can lead to extra delay where we don't need to apply.
> The current proposed approach can take other loads or factors
> (network, busyness of the publisher, etc) into account
> because it calculates the required delay on the subscriber.

I don't think it's OK to just loose the ability to read / reply to keepalive
messages.

I think as-is we seriously consider to just reject the feature, adding too
much complexity, without corresponding gain.

Greetings,

Andres Freund