[mythtv-users] Slow program listings and deleting

Nick Morrott knowledgejunkie at gmail.com
Wed May 16 12:49:45 UTC 2007

On 16/05/07, Rob Willett (Mythtv) <rob.mythtv2 at robertwillett.com> wrote:
> Hi,
> I'm trying to analyse why my MythTV system occassionally works slowly on
> program listings and deleting recorded programs.


> So my questions are, since you've got this far,
> 1) Should the table recordmatch be so large? Is 4,000 entries a lot?

I depends on how many recording rules you have, how many results they
generate per video source, and how many video soures you have defined.
Do you have any rules which return many results, such as genre
searches, or are they specific to program titles? If you remove any
rules which have been created recently, does performance revert to its
previous level?

> 2) Should data be deleted from this table? if so how?

No. This should happen automatically during rescheduling and after
listings updates.

> 3) What sizes are other peoples recordmatch tables?

I currently have 288 records in recordmatch, generated from 2 video
sources and 54 recording rules.

> 4) Does the monster SQL statement above look familiar? Does it have form
> as a slow query? Are there additional indexes that could be created? I
> did an EXPLAIN on it, but it doesn't give me any real help.

You can check http://cvs.mythtv.org/trac/browser/trunk/mythtv/libs/libmythtv/dbcheck.cpp
and cross-reference your installation's DBSchema version to ensure you
have the intended indexes - if you have any missing you can recreate

> 5) Any suggestions as to what to do?

Check your video sources/channels and make sure you do not have any
extraneous channels/listings data in the database. I can't say whether
upgrading to 0.20-fixes would help you out here.


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