[mythtv-users] Database internals

[jedi]

On Sun, Jan 05, 2014 at 08:40:02AM +0000, Paul Gardiner wrote:
> Craig Cook <cncook001 at yahoo.com> wrote:
> >>> Which means no foreign keys, one area where an inconsistent backup
> >would
> >>> likely result in the cataclysmic fail on restore predicted on this
> >>> 'chere list.  And as you pointed out, it also doesn't support
> >>> transactions which means --single-transaction in mysqldump is,
> >>> well...doesn't really do much for myisam.
> >>
> >>Am I reading this right? That's a good thing. So MythTV can't be using
> >>foreign keys, hence one less trap to fall into.
> >
> >I was going to say the opposite.  Foreign keys are usually a good
> >thing.
> 
> Sorry "good thing" was a bit ambiguous. I meant, the lack of foreign key use in mythtv implies there is one less way in which a mysqldump-based backup might fail.

   No. It means that you can't depend on referential integrity EVER and you
always have to approach the data with that in mind. So trying to blame the
end user for "backing it up wrong" just becomes utterly absurd. You always
have to consider the possibility that your own code trashed your own schema
and then deal with it.