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...


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PGConf.EU 2019
Oct 15-18, 2019
Milan, Italy
Postgres Open 2019
Sep 11-13, 2019
Orlando, FL, USA
Postgres London 2019
Jul 2-3, 2019
London, UK
PGCon 2019
May 27-31, 2019
Ottawa, Canada
PGDay.IT 2019
May 17, 2019
Bologna, Italy
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