Re: Postgres open source upgrades

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.)

--
Karl Denninger
karl(at)denninger(dot)net
/The Market Ticker/
/[S/MIME encrypted email preferred]/