[debian-mysql] Bug#853008: Bug#853008: mysql-server-5.7: purge could delete mariadb-server files with inadequate warning

[Lars Tangvald]

On 01/31/2018 02:19 PM, Olaf van der Spek wrote:
> Hi,
>
>> Anyone else have any good ideas on how to handle this?
> I do. The solution is quite simple: do not, ever, remove user data / databases.
>
> It makes everything so much simpler, both on the user side and on the
> dev side. No weird questions when installing, no databases gone by
> accident..
>
The problem is that MariaDB and MySQL use the same data location, so 
you'd instead get weird errors when trying to move to a variant/version 
that can't handle the old data (MySQL does not support migration from 
MariaDB, and MariaDB supports specific versions of MySQL). It's 
reasonable for a user to expect that purging one package would let them 
install the other without issues.

There is work going on to deal with this, which should both let users go 
back and forth between incompatible versions and make sure a package can 
only delete its own data.

--
Lars