The worlds smallest Slony cluster?

We recently updated on of our Slony clusters. I think it at least used to qualify as one of the worlds smallest ones:

  • Two nodes (obvious minimum)
  • one database (that's a given)
  • with one table
  • with one column
  • with one row

Now, we recently doubled the size of this cluster. It now has a whopping two columns in the table. The second column being updated by a trigger, so it's still only one column updated by the end user (well, application). But it's two columns to be replicated!

So what does this prove? Really, not much, but at least: Slony certainly scales "downward" just fine. It feels like a bit overhead to set it up for something like this, but it works just fine. Even in a small database, triggers can be very useful - regardless of what the documentation of a certain other database used to say before... And even in a trivial case like this, statement based replication simply does not work reliably*. You need something that's data based - something that the same other database is actually recognizing now and will be including the next version...


Conferences

I speak at and organize conferences around Open Source in general and PostgreSQL in particular.

Upcoming

Stockholm PUG 2016/4
Aug 31, 2016
Stockholm, Sweden
Postgres Open
Sep 13-16, 2016
Dallas, USA
Postgres Vision 2016
Oct 11-Nov 13, 2016
San Francisco, USA
PGConf.EU 2016
Nov 1-Jan 4, 2016
Tallinn, Estonia
PGConf.Asia 2016
Dec 2-3, 2016
Tokyo, Japan

Past

PG Day'16 Russia
Jul 6-8, 2016
St Petersburg, Russia
PGDay UK 2016
Jul 05, 2016
London, UK
Stockholm PUG 2016/3
Jun 16, 2016
Stockholm, Sweden
PGCon
May 17-21, 2016
Ottawa, Canada
Pycon Sweden
May 9-10, 2016
Stockholm, Sweden
More past conferences