akonadi-server should not depend explicitly on akonadi-backend-mysql

[Raul Dias]

There are 3 different backends for akonadi-server:
akonadi-backend-mysql
akonadi-backend-postgresql
akonadi-backend-sqlite

all of them should provide a metapackage (e.g. akonadi-backend) and akonadi-server should depend on the metapackage.

ProblemType: Bug
DistroRelease: Ubuntu 18.10
Package: akonadi-server 4:18.04.3-0ubuntu2
Uname: Linux 4.18.18-041818-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.10-0ubuntu13
Architecture: amd64
CurrentDesktop: KDE
Date: Wed Nov 14 12:00:39 2018
InstallationDate: Installed on 2014-05-12 (1647 days ago)
InstallationMedia: Error: [Errno 13] Permission denied: '/var/log/installer/media-info'
SourcePackage: akonadi
UpgradeStatus: Upgraded to cosmic on 2018-10-22 (23 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[somekool (somekool)]

Yes please !
we need this
please remove the hard dependency on mysql backend

could switching backend offer to migrate the configuration, and clean/purge the previous storage?

the only doc I found for sqlite is https://www.legendiary.at/2012/03/13/change-akonadi-backend-to-sqlite3/

[somekool (somekool)]

still valid as of 19.10

[somekool (somekool)]

please note, akonadi is not officially supported as a backend

> Why not use sqlite?
> We tried. Really. It just can't handle the concurrent access very well.

ref: https://techbase.kde.org/KDE_PIM/Akonadi

I suggest we move it to experimental

[somekool (somekool)]

Note, with MySQL
I often get this migration error

> org.kde.pim.akonadiserver: "\nSql error: Duplicate column name 'version' QMYSQL: Unable to execute query\nQuery: ALTER TABLE SchemaVersionTable ADD COLUMN version INTEGER NOT NULL DEFAULT 0"
org.kde.pim.akonadiserver: Unable to initialize database.

I delete or move away the db_data to "Start over"

[somekool (somekool)]

would be nice to have this solved before 20.04 LTS

Thank you