Backstory: I had a debian 11 VPS. I installed the postgresql program from the debian 11 apt repo, back a few months ago. Back then, it was postgres 13 on the debian stable repos.

Fast forward couple months: debian 12 comes out. I do a “apt dist-upgrade” and in-place upgrade my VPS from debian 11 to debian 12. Along with this upgrade, comes postgresql 15 installed.

Now, fast forward couple more months: lemmy 0.18.3 comes out. I do not upgrade (I am on lemmy 0.18.2—afaik).

Fast forward some time, too: lemmy 0.18.4 comes out. I decide to upgrade to 0.18.4 from my existing 0.18.2.

I pull the git repo. Compile it locally. It goes well, no errors in the compilation process. I stop the lemmy systemd service, then I “mv” the compiled “lemmy_server” to /usr/bin dir.

I try to restart the now-upgraded lemmy systemd service. However, the systemd service fails.

I check the sudo journalctl -fu lemmy and I see the following error message:

lemmy_server[17631]: thread 'main' panicked at 'Couldn't run DB Migrations: Failed to run 2023-07-08-101154_fix_soft_delete_aggregates with: syntax error at or near "trigger"', crates/db_schema/src/utils.rs:221:25

I report this issue here: https://github.com/LemmyNet/lemmy/issues/3756#issuecomment-1686439103

However, after a few back and forths and internet search, I conclude that somewhere between lemmy 0.18.3 and 0.18.4, lemmy stops supporting psql <15. So, my existing DB is not compatible.

Upon my investigation on my VPS setup, I concluded that psql 15 is running, however, lemmy is using the psql 13 tables (I do not know if this is the correct term).

Now my question: is there a way to import the lemmy data I had in the psql 13 tables to a new psql 15 table (or database, I don’t know the term).

To make things hairier: I also run a dendrite server on the same VPS, and the dendrite server is using the psql 15 with psql 13 tables on the same database as the lemmy one.

The dendrite database is controlled by a psql user named “dendrite” and the lemmy database is controlled by a psql user named “lemmy” . I hope this makes differentiation between two databases possible. And so I do not harm my existing dendrite database.

Any recommendations about my options here?

  • RoundSparrow@lemmy.mlM
    2·
    1 year ago

    It looks to me like Lemmy found an empty database and issued all the migrations of a new install…

    So that database URL we gave it was wrong, or the restore we did was wrong parameters, etc.

    And, like I mentioned, some confusion already happens with your federation status as I think it rushes out to register itself as a new server with the Lemmy network. And some data got in…

    So… I’m not sure what to do figure this out. We could do a pg_dumpall of your PostgreSQL 15 data and then sift through it and see if we can make sense of how this happened?

      • RoundSparrow@lemmy.mlM
        2·
        1 year ago

        I’ve never switched a system from config.hjson or wahtever file over to URL - maybe the /lemmy on the end is wrong?

          • RoundSparrow@lemmy.mlM
            2·
            1 year ago

            it would answer how this happened… but we do need to find the syntax for port in lemmy.hjson

            (And then open a bug that the documentation isn’t exactly clear on that page I linked!)

            • Anark Karabey@monero.townOP
              2·
              1 year ago

              Alright. For now let’s give a break. I need to sleep. I will return tomorrow the same hour we started today. So, it will be like 18 hours into the future. Thx for your help. I hope to talk to you soon.