Just switched to postgresql on my archlinux box. Procedure:

install postgresql and postgresql-old-upgrade
stop akonadi
move .local/share/akonadi away
edit .config/akonadi/akonadiserverrc setting the driver to QPSQL
start akonadi

I lost my filters, and oddly, the sent forlder for this mail is unset. But=
=20
everything works basically :-)

Anders

s=C3=B8ndag den 7. april 2019 20.05.55 CET skrev Dominique Dumont:
> On Sunday, 7 April 2019 00:07:51 CEST Matthias M=C3=BCller wrote:
> > I've read a lot of switching from MySQL to MariDB or PostgreSQL or vica
> > versa or =E2=80=A6
> >=20
> > But: How to do that?
>=20
> On my Debian I did:
>=20
> - apt install akonadi-backend-postgresql postgresql
> - in kontact, export all filters to a file
> - delete filters
> - stop kontact
> - akonadictl stop
> - rm -r .local/share/akonadi/*
> - mkdir .local/share/akonadi/db_data
> - edit .config/akonadi/akonadiserverrc to set Driver=3DQPSQL in %General
> section - akonadictl start
> - then open kontact (or kmail).
> - then the mails are downloaded from servers
> - import the filters that were imported previously
>=20
> There's no need to redo the account configuration. But folder properties
> (like expiration) are lost.
>=20
> Hope this helps