[mythtv-users] Is this database corruption?

[Michael T. Dean]

On 04/28/2015 11:11 PM, James Miller wrote:
> I've noted some oddities in the TV schedule on my newly-installed 
> MythTV (0.27..20140303-1 Gentoo), and even had a recording fail owing 
> to what I believe was a schedule glitch. I'm wondering whether my 
> database might have gotten corrupted somehow. I'm a schedules direct 
> subscriber, by the way.
>
> Here are some symptoms. First, I see that channel listings can display 
> programming from other channels. In some previous testing I noted, for 
> example, that sometimes under channel 4_1 I see programming for 
> channel 41 (that does not seem to be the case at the moment). Another 
> thing I'm seeing is that a program's title and description do not 
> match. An example would be a recording currently in the database whose 
> title is "Knit and Crochet Now!" but whose description reads "Green 
> Paths - Mon, Denmark: Host Claus Meyer visits the white-cliffed island 
> of Mon, in the south of Denmark, on a crisp and clear winter day. 
> There, he makes vitamin-packed juice and cooks codfish on the beach. 
> Recipes: Raw Winter Vegetable Juice; Roast Leg of Goat with Blue 
> Cheese, Herb Salad, Hazelnuts and Green Kale Dressing; Steamed Cod 
> Fillet with Fried Cod Roe, Winter Leeks and Apples."

Almost always caused by using XMLTV or Schedules Direct for a channel 
and also enabling EIT--so the two walk over each other's data and give 
you bad data.

> Clearly there is some error here. Finally, over the past weekend I 
> found in the schedule a program I wanted to record, selected it, and 
> opted for "record only this showing." Later, when the recording should 
> have been in progress, I noted the tuner was not active. When I went 
> to check on why it was not recording, there was a message to the 
> effect that it was not recording because the program was "not listed."

This is because the listing had changed from the time you scheduled it 
so that it was a different listing at record time.  The change could 
have even been a 1s start time difference, in which case a "this 
showing" rule would not match.  Again, this points to using EIT on the 
channel.  Based on the earlier symptom you've described, I do not think 
you want EIT enabled on the channel(s)--or possibly on any channel in 
the Video Source (in which case just disable EIT on the Video Source).

> Fortunately it was early enough in the showing that I could just 
> reschedule it.
>
> Are these indications that the database has gotten corrupted?

Nope.  Database corruption wouldn't cause changing data.

> I tried already, many times while going through the initial set-up, 
> deleting, then reconfiguring capture cards and downloading schedule 
> information anew. Could something have gotten corrupted in that process?

Yes, it was corrupted by not reconfiguring it properly--which is 
actually a very common issue.  It is unfortunate that MythTV requires so 
much user-specified configuration to work properly, but MythTV is trying 
to support so many use cases around the world with so many different 
allowable hardware configurations that the price for that genericity (is 
that a word?) is paid in configuration.

Eventually, it would be nice to disable EIT on any channel receiving 
non-EIT listings data since that's always a broken configuration, but no 
one has gotten around to making the change, yet.

> This is still a pretty new installation, by the way. So I would have 
> no problem deleting the whole MythTV configuration and starting over 
> afresh. Input will be appreciated.

No need.  Just configure the system appropriately so that you are not 
using EIT (over-the-air listings) on any channel that uses XMLTV or 
Schedules Direct listings.

Mike