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

SCALE 18x
Mar 5-8, 2020
Pasadena, USA
Nordic PGDay 2020
Mar 24, 2020
Helsinki, Finland
pgDay.paris 2020
Mar 26, 2020
Paris, France
PGCon 2020
May 26-29, 2020
Ottawa, Canada
PGConf.EU 2020
Oct 20-23, 2020
Berlin, Germany

Past

FOSDEM PGDay 2020
Jan 31-Feb 2, 2020
Brussels, Belgium
PGDaySF 2020
Jan 21, 2020
San Francisco, USA
DevOpsSaar
Dec 5, 2019
Saarbr├╝cken, Germany
Stockholm PostgreSQL Meetup
Dec 3, 2019
Stockholm, Sweden
Berlin PostgreSQL Meetup
Nov 21, 2019
Berlin, Germany
More past conferences