Our production environment has been using PostgreSQL for more than 5 years (since this project started). We have been using Slony-I as our replication mechanism. I am interested to find out the pros and cons of Slony vs the built-in replication in 9.0. Based on what I understand:
* Slony has a higher overhead than the binary replication in 9.0
* When using Slony, schema change must be applied via slonik (in most cases)
* Unfortunately, IMO it is easy to make a mistake when applying schema changes in Slony, fortunately, it is easy to drop and recreate the replication sets
* Slony is an asynchronous replication mechanism
* Slony allows you to replication some tables, while ignoring others
* PostgreSQL 9.0 with hot standby & streaming replication is an asynchronous replication mechanism
* Overhead is low compared to Slony
Are there some cases where it is better to use Slony, for example, when you must specifically exclude tables from replication? I believe our system will be better off using the built-in replication mechanism of 9.0, and I am guessing most people will be in the same boat.
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John L Cheng
