[mythtv] Ticket #8679: mythfrontend deletes settings when db connection is "weak" (was Re: Please unlock ticket)

[Michael T. Dean]

  On 07/26/2010 01:10 PM, Thomas Börkel wrote:
> On 26.07.2010 18:47, Michael T. Dean wrote
>>> Of course it is really strange, that the mysql client lib reports
>>> failures for both the SELECTs and DELETEs, but in fact the DELETEs
>>> succeeded. But that is another story.
>> FWIW, the message you're getting is exactly the message that the
>> Qt-MySQL drivers (incorrectly) report when you submit invalid SQL that
>> references non-existent tables or columns or similar.
> I see in my backup, that the settings and displayprofiles are there.
>  From there I got the data that I restored after the incident.
>> Therefore, it's quite possible the whole problem is that your database
>> schema is broken and some table or column is missing.  You could do a
> Sorry, but did you read my previous messages here?
>
> I wrote several times, that the whole system normally runs perfectly and
> only about once a month (so far 3 times) this problem occurs. And a
> restart of the mythfrontend process fixes it.
>
> If the database schema was broken, what it ever run without errors?

Yes, until it hit the code that issued the SQL that won't work with your 
schema.

On an unrelated note, (but just to make the point that broken schemas 
aren't noticed immediately) this is exactly why we recommend against 
users doing things to the DB.  When someone breaks the DB (either the 
data or the schema), they create a ticking time bomb.  Generally, by the 
time they notice a failure, it's been long enough that they no longer 
suspect that the "fixing" they did is what caused it.

Mike