[mythtv] backend from SVN 9761 bangs on mysqld

Stuart Auchterlonie stuarta at squashedfrog.net
Mon Apr 24 10:31:30 UTC 2006

On Sun, Apr 23, 2006 at 06:43:44PM -0400, Daniel Kristjansson wrote:
> On Sun, 2006-04-23 at 23:58 +0200, Janne Grunau wrote:
> > I think it's best to start with a clean cache but the problem persists 
> > then too. If we miss the update to the maximum version number we won't 
> > update until the next time.
> You will have to discuss this with Stuart A, he understands the
> low pid priority scheme in the DVB EIT much better than me.

pid/tableid priority discussed in the previous email.

There are two ways of doing this. Either do nothing and take
the hit for the first 15min or so while the cache is build, or
add some extra fields to the program table, and insert the cache
key & value into those fields when the data is inserted in to the
DB. On a new startup we can just read all this info back into the

These key & data values could also be put to other use. In the
case where people like to use grabber data as well as EIT, this
could be used to identify data sourced from the grabber.

> > > BTW The data 
> > > does need to be stored in the DB, even the EIT version cache becomes
> > > too big after a while. (But not nearly as big as the cache of the
> > > entire EIT event that 0.19 uses.)
> > I don't think using the db for the cache is a good idea. The greatest 
> > parts of the EIT-scanning are atm queries. So adding more is not the 
> > solution even if these queries are cheaper.
> But this is one query per channel, that saves us hundreds of megabytes
> of RAM..

I seriously doubt it is in the region of hundreds of megabytes...

> > No, not really. I changed score_match in such a way that only a perfect 
> > match can archieve a score of 12000. But Stuart Auchterlonie and I are 
> > both not sure what you want to archieve with the second part of that 
> > function. See attached diff.
> So if the ending time of the program changed you could pick this up by
> looking at the title or the description? :)

If the program data changes it is MANDATORY to change the version
number on the EIT data table.

There is also talk of rolling out Running Status Table (RST) support
which is designed to indicate that a program starts early or late etc.


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