On 6/28/2022 16:09, Bruce Momjian wrote:
On Tue, Jun 28, 2022 at 12:13:11PM -0700, Teja Jakkidi wrote:
Hello pgsql-admin,
I am very new to Postgres and trying to learn how upgrades work in Postgres.
We have open source installation and I am wondering if anyone can help me with correct documentation or steps on performing minor and major version upgrades.
Please look here:
https://www.postgresql.org/support/versioning/
There are links to the documentation there.
To add to this from real-world experience over a long period of time (I've been using this code since the 1990s!) with Postgres:
I've never had a minor version upgrade blow up in my face. Major version upgrades require some care because if the "upgrade in place" procedure is used and something goes wrong with it you can be in serious trouble. It's supposed to check that but if it goes bad on you then I hope you have a valid and recent backup as you can be in extremely serious trouble if not. Theoretically the in-place process should check first and refuse to proceed if there's a problem but if you haven't met Mrs. Murphy I recommend thinking a long time before proceeding with that in the absence of a mitigation strategy with data you care about.
Exactly how you mitigate that risk requires some thought and much depends on prior planning (the obvious is to not upgrade in-place and thus the "pre-upgrade" copy, and the binaries, are still there in case something goes wrong -- but that requires both the processing time and disk storage for the second copy.)