[mythtv-users] Slow MySQL query after delete

Michael T. Dean mtdean at thirdcontact.com
Sat Nov 24 15:47:02 UTC 2007

On 11/23/2007 11:27 PM, Larry K wrote:
> On 9/6/07, crs23 <pvr at groundhog.pair.com> wrote:
>> Michael T. Dean wrote:
>>> I don't think much testing has been done on systems having identical
>>> recording rules.  Though it shouldn't cause issues, cleaning out the
>>> duplicates (triplicates?  whatever) would significantly simplify the
>>> query's processing, so doing so would be very much to your advantage.
>> Done and the improvement was substantial.  There were several multiple
>> entries.  One program had about a dozen duplicate entries and that just
>> happened to be the program with the most previously recorded episodes.  I
>> also changed the recordings to be on a particular channel instead of any
>> channel which I think helped to.
>> I'm now down to ~150,000 rows examined in 5.5 seconds, 696 rows
>> returned.  5
>> or 6 seconds is hugely better but still a bit of an annoyance.  But I'm
>> very
>> pleased with the results so far and the incredible support I've received
>> on
>> this forum.  Thank you to everyone!
> What was your method to determine the duplicates?  And did you simply issue
> a SQL delete to get rid of them, or some other mechanism?
Pretty sure he just went through MythWeb's Recording Schedules page or
mythfrontend's Recording Priorities page to find overlaps.  The problem
is that they're not necessarily identical duplicates (that was a
"shortcut" I typed to convey the idea to the OP)--just multiple rules
that match the same showings in many places.  So, you'll need some human
judgment involved to find them.

Besides, if you edit the record table directly, you'll leave all sorts
of other stuff behind that is likely to cause even more problems than
having "identical" recording rules.


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