[mythtv-users] LiveTV channel switching time

Brad DerManouelian myth at dermanouelian.com
Fri Dec 1 21:22:25 UTC 2006

On Dec 1, 2006, at 1:10 PM, Stef Coene wrote:

> On Friday 01 December 2006 21:19, Dag Nygren wrote:
>>> So I set up a poll for the shy (and not so shy) people at:
>>> http://micropoll.questionpro.com/akira/MicroPoll?mode=html&id=19713
>> OK,
>> about 10 days, 127 votes and 60% think it is a problem.
>> (The poll will be there until Dec 19th)
>> So now back to your boxes and do some profiling to find out where
>> the channel change time is spent. (A least I will try)
> I finally had the time to debug "my" livetv problem:   
> optimize_mythdb.pl was
> the solution.  You can find it in the contrib directory.
> Yesterday, I replaced my backend and the live tv problems were  
> gone.  So I
> redid the upgrade step by step and I found out that the mysql  
> database was
> the problem.
> After an export / import, live tv was a bit faster.  Running
> optimize_mythdb.pl solved "everything".  Starting livetv takes 5  
> seconds,
> switching channels less then 0.5 sec.
> This datbase is an upgrade from 0.19 ot 0.20.  Is it possible that  
> the upgrade
> messed up something?
> Stef

Probably nothing the upgrade missed, but rather MySQL not  
automatically keeping its tables optimized. Glad your channel change  
problems are gone! For the record, it's been recommended that the db  
optimize be run as a cron job daily to prevent such issues. Maybe  
that's why the devs aren't seeing the problem since they're likely  
all doing this.

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