Re: BDR DML Only

Hi,

On 2014-09-16 19:32:38 +0200, pba(at)mailme(dot)dk wrote:
> I am not sure I have a very good case other than the very lousy argument
> that I would trust it to be stable much more quickly :-)

Well, we'll get the much more quickly if people report problems ;)

> I tried it and it works fine for the simple examples, but obvious once
> things get a bit more complicated my case falls to pieces.
>
> Trying to load the postgis extension then fails. It worked with DDL at
> least on the first attempt. So we are back to the error recovery.

Hm, that's a bit odd. I think that should actually work. Which version
did you use?

> As far as I can see it will still "block" DDL operations on the second
> server even if they are not replicated.

That's a security feature. You can circumvent it, but I'd strongly
advise against it. It's unproblematic if you have only one node being
written to, but if you DDL against a table which is written to by
multiple nodes you can very quickly get into nasty situations. Consider
a table with one column being written to on three nodes. It gets a
column added to it. Some nodes will have pending changes with 1 column,
others with 2. In neither case it's clear how to replicate these.

Greetings,

Andres Freund

--
Andres Freund http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services