[mythtv-users] DB charset pre-conversion test failed! Your database seems to be partially corrupted.

Michael T. Dean mtdean at thirdcontact.com
Mon Nov 9 19:19:40 UTC 2009

On 11/09/2009 01:55 PM, Brian J. Murrell wrote:
> On Mon, 2009-11-09 at 13:42 -0500, Michael T. Dean wrote: 
>> Let's just put it this way:  If your database is so messed up that 
>> you're missing tables, how can you be sure there's no other breakage.  
> The implication I think was not that the database had gotten "broken" at
> some point but just that some add-on, like (say) mythvideo had been
> installed and another like (say) mythdvd had not been and therefor the
> tables that the latter would have used were never created but that the
> assumption was being made that they were there given the presence of the
> tables from the former.

Each plugin does its DB upgrade separately and only touches its own 
tables.  This is actually why--on first starting mythfrontend after 
upgrading to 0.22+ --you will get prompted 2 times about whether or not 
to allow a DB upgrade (once for MythMusic DB schema upgrade and once for 
MythVideo DB schema upgrade--the other plugins haven't been updated to 
ensure that a DB backup was made and to prompt the user for permission 
to upgrade the DB).  Therefore, this will not affect the 
mythbackend/mythtv-setup TV database schema upgrade in any way.

> I really tend to doubt that my database has simply "broken down".
> Everything works just fine.  I'd expect the things that I have installed
> and am using would complain if there was general database brokenness.

See below.

>> Note that even if you compare schema to a known, working configuration, 
>> and make yours identical, you still have no idea how broken the /data/ 
>> is.
> I will still assert that I really doubt that I have a "broken" database
> in the sense that you are implying.  Perhaps my database is not
> conforming to the schema that the 0.22 database upgrader is assuming,
> but I really don't think there is any general brokenness.

If your DB schema isn't the schema for which MythTV was designed--the 
one that's created by MythTV--I consider that broken.

>> And, since the /whole/ purpose of the database is to store 
>> important data, do you really want broken data...
> Again, I will be VERY surprised if I have "broken data".  As I have
> said, *everything* works just fine in 0.21.  Not a single hitch at all
> from any of several frontends.  Would you really expect that if there
> was general brokenness of the data to the point that it could not be
> trusted?

Yes--because I doubt that you use (or, should I say, "notice") all the 
functionality MythTV provides.

> I am much more suspecting of a bug in the database updater, making some
> kind of assumption which is just not true in my case, or the other
> mentioned case(s).

Upload a gzip'ed or bzip2'ed copy of your pre-upgrade (0.21-fixes/1214 
DB schema version) database to http://filebin.ca/ and e-mail me a link 
(directly--not on list--and using the same subject so I don't lose it) 
and I'll tell you exactly what's broken.  I /still/ recommend you use 
the approach I mentioned to upgrade--because broken data means broken 


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