Re: BDR - triggers on receiving node?

On 25 March 2015 at 20:14, Peter Mogensen <apm(at)one(dot)com> wrote:

>
>
> On 2015-03-25 12:32, Craig Ringer wrote:
>
>> On 25 March 2015 at 19:15, Peter Mogensen <apm(at)one(dot)com> wrote:
>>
>> Say ... I have a table in a BDR replicated database with an "ON UPDATE"
>>> trigger. - and that trigger wants to locally find out the local
>>> txid_snapshot_xmin() when a change was applied to the local node.
>>>
>>> Why would you want to do that? Just out of interest?
>>
>>
>>
> Because I have a bunch of SELECT queries to the local node, which includes
> the txid_current() in their result, and I want to be able to recognize a
> result which was obtained prior to a change reaching the local node.
>

So you're trying to do cache invalidation / cache verification of some form?

I'm interested in what you're looking at doing, but would probably need a
more complete description to offer much input.

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