Mysql and Maria are at odds - again

[Don B. Cilly]

Dazed and confused. Posting just in case anyone is interested - now or in the future.
I uninstalled both mysql and mariadb. Updated. It boots just fine.
So far so good. What puzzles me is that my sql-dependent apps work just fine without any mysql or replacements.

[Don B. Cilly]

After today's update, my neon wouldn't boot... well, it would boot, but get stuck at "can't get the friggin' mariadb to work".
I tried systemctling it out, then it complained the mysql thing (which I don't have) wouldn't initialise - and refused to budge.

After a few more tries, I restored from backup... a bit old, still on Plasma 5.20.
Any suggestions as to what to try and apt-hold before I try updating again? :-/

[Don B. Cilly]

Personally I have no use for mysql. A few apps I have, use it. They installed it. No additional repos, just as dependencies.
So I didn't like the idea of removing it, as I said, those will stop working.
It turns out mariadb is a full replacement for it, but nobody - not the web, and not apt - told me. Apt just whined and whinged.
No amount of -- fix broken installs would even suggest a solution.
Just the "classic" this depends on that, that depends on this, it's not going to be installed, creek, no paddle, goodbye.

So one turns to the forums and expert advisers, they all say, uninstall mariadb (or just delete the config file).
Which worked for a while, actually. Then apt was back at it - with a vengeance.

Now it seems to me, the solution is to uninstall mysql instead - it seems to work flawlessly so far.
The question obviously is, why do I have to do it, and waste countless hours finding out (well, experimenting to find out) when apt - when installing mariadb (which it didn't really tell me about, I mean, it sneaked in among a big list of packages didn't it) should have been the one to do it?
Like, the following packages will be removed and all?

[jlittle]

I gave up on MySql because I developed the perception of the negative influence of Oracle on the project. I'd adopted MySql as my go to db years before, and at that time I'd reviewed the assurances from the project that it was independent of Oracle, and accepted them.

So I decided to switch to MariaDB, but at the same time I checked out alternatives. A user like me has to know a little about sqlite; for example, firefox uses it a lot, and it's good for what it does, but there's what's been called the "bizarro type system". However, I looked at postgresql, and for me it's far better. Coming from on-line transaction processing databases, I found that MySql has a lot of clunkiness, and non-standard bits that tripped me up. Postgresql is more standards compliant, and where it isn't is documented well. I worried about losing MySqlWorkbench, which I liked, but I found SQL Workbench/J which is nearly as good, is more open, not tied to any particular database, and has better dark mode support.

[Don B. Cilly]

I tried the "workaround" in the bug report. It didn't work.
I tried all sorts of esoterics from the webspace pundits. They didn't work.
So,

Question: Why two different database servers on the same machine?

got me thinking. Why indeed. One would think only one is needed. But I already removed one (mariadb) and apt still complains...
I investigated a little. Well, it seems the folks at Canonical (or wherever) decided mariadb is meant to replace mysql, and it's "100% compatible".
They just seem to have forgotten that to use one, you have to uninstall the other.

Now, all suggestions pointing to uninstalling/removing configs for, mariadb - and knowing that some of my apps used mysql... that sort of made sense.
Except, it didn't work did it.
So what I did, backed everything up, uninstalled mysql, installed mariadb, rebooted, and... all my mysql-dependent apps work just fine, and apt is happy - no conflicts.

So the solution seems to be, don't remove mariadb, remove mysql and maria will work "as" it.

[oshunluvr]

Question: Why two different database servers on the same machine?

I need several myself (postgres, firebird, and sqlite at this time, often others). I've learned it's much easier to run the database servers in VMs alone and then access them from front-ends or terminal consoles. Seems to work pretty well, is transportable, and removes conflicts. I do this both in Linux and Windows environments. Just an idea...

[claydoh]

Related?
https://bugs.kde.org/show_bug.cgi?id=432504

[Don B. Cilly]

Well, merely removing the 'reference' to mariadb in /etc/apt/preferences.d did work - a few months ago.
And that was after purging her
But then Maria somehow managed to raise a conflict even from... the tomb.
I have no marias anywhere.

~$ locate maria
~$

[Snowhog]

What it seems to be to me, is that merely removing the 'reference' to mariadb in /etc/apt/preferences.d while (assumed) you didn't actually uninstall/purge maria (?) is your issue. IF maria (?) is still installed, that is the cause of the conflict being reported.

[Don B. Cilly]

I do realise this is not really "K" related, it's very much a "U" thing, so I should ask on ubuntuforums rather than here.
But then, that is not a particularly friendly forum, and this is, so...

A few months ago, I couldn't do a "clean" update, due to mysql conflicts.
Trial-and-erroring after extensive searching, I managed to solve it by removing /etc/apt/preferences.d/50-neon-mariadb .
For the past few days, I've been getting

The following packages have been kept back:
mysql-client-core-8.0 mysql-server-core-8.0

Again. And

Broken mysql-server-8.0:amd64 Depends on mysql-server-core-8.0:amd64 < 8.0.23-0ubuntu0.20.04.1 -> 1:0.0+p20.04+git20210201.1401 @ii umU > (= 8.0.23-0ubuntu0.20.04.1)
Considering mysql-server-core-8.0:amd64 -1 as a solution to mysql-server-8.0:amd64 0
Added mysql-server-core-8.0:amd64 to the remove list
Fixing mysql-server-8.0:amd64 via keep of mysql-server-core-8.0:amd64
Investigating (0) mariadb-server-core-10.3:amd64 < none -> 1:10.3.25-0ubuntu0.20.04.1 @un uN Ib >
Broken mariadb-server-core-10.3:amd64 Conflicts on mysql-server-8.0:amd64 < 8.0.23-0ubuntu0.20.04.1 @ii mK >
Considering mysql-server-8.0:amd64 0 as a solution to mariadb-server-core-10.3:amd64 0
Holding Back mariadb-server-core-10.3:amd64 rather than change mysql-server-8.0:amd64
Try to Re-Instate (0) mysql-server-core-8.0:amd64
Try to Re-Instate (1) mysql-client-core-8.0:amd64
Done

Again. Thing is:

~$ ll /etc/apt/preferences.d/
total 32K
drwxr-xr-x 2 root root 4.0K Feb  6 16:22 ./
drwxr-xr-x 7 root root 4.0K Feb 10 08:06 ../
-rw-r--r-- 1 root root  791 Aug  3  2020 50-neon-ubuntu-release-upgrader
-rw-r--r-- 1 root root 2.2K Jan 14 14:31 99-focal-overrides
-rw-r--r-- 1 root root  212 Aug 18 10:14 99-neon-base-files
-rw-r--r-- 1 root root  174 Sep  6  2019 99-neon-qca
-rw-r--r-- 1 root root   72 Sep  6  2019 99-neon-software-properties
-rw-r--r-- 1 root root  136 Sep  6  2019 99-pulseaudio-qt

and

~$ locate maria
~$

Now, searching - again (all "agains" are in a Forrest Gump Voice ;?), I can't find anything new, so,
if anyone has a suggestion... well, good :?), otherwise... I can imagine.