Re: logical changeset generation v4 - Heikki's thoughts about the patch state

On 24.01.2013 00:30, Andres Freund wrote:
> Hi,
>
> I decided to reply on the patches thread to be able to find this later.
>
> On 2013-01-23 22:48:50 +0200, Heikki Linnakangas wrote:
>> "logical changeset generation v4"
>> This is a boatload of infrastructure for supporting logical replication, yet
>> we have no code actually implementing logical replication that would go with
>> this. The premise of logical replication over trigger-based was that it'd be
>> faster, yet we cannot asses that without a working implementation. I don't
>> think this can be committed in this state.
>
> Its a fair point that this is a huge amount of code without a user in
> itself in-core.
> But the reason it got no user included is because several people
> explicitly didn't want a user in-core for now but said the first part of
> this would be to implement the changeset generation as a separate
> piece. Didn't you actually prefer not to have any users of this in-core
> yourself?

Yes, I certainly did. But we still need to see the other piece of the
puzzle to see how this fits with it.

BTW, why does all the transaction reordering stuff has to be in core?

How much of this infrastructure is to support replicating DDL changes?
IOW, if we drop that requirement, how much code can we slash? Any other
features or requirements that could be dropped? I think it's clear at
this stage that this patch is not going to be committed as it is. If you
can reduce it to a fraction of what it is now, that fraction might have
a chance. Otherwise, it's just going to be pushed to the next commitfest
as whole, and we're going to be having the same doubts and discussions then.

- Heikki