Grant Fritchey explains why stateful systems are difficult to roll back:
The invitation this month for #PGSqlPhriday comes from Dian Fay. The topic is pretty simple, database change management. Now, I may have, once or twice, spoken about database change management, database DevOps, automating deployments, and all that sort of thing. Maybe. Once or twice.
OK. This is my topic.
I’ve got some great examples on taking changes from the schema on your PostgreSQL databases and then deploying them. All the technical stuff you could want. However, I don’t want to talk about that today. Instead, I want to talk about something really important, the concept of rollbacks when it comes to database deployments.
I completely agree with Grant’s description of the pain and his recommendation. With stateful systems, roll forward, not backward.