[mythtv-users] 0.25 SQL CPU Load issues after optimisation

Another Sillyname anothersname at googlemail.com
Fri Jul 20 20:03:24 UTC 2012


On 20 July 2012 20:18, Gary Buhrmaster <gary.buhrmaster at gmail.com> wrote:
> ....
>> Well, I have not tried this (I am not in a position to test at the moment),
>> but you may be able to just take the sql you have identified, and
>> use the mysql cli, type in 'EXPLAIN ' and then copy/paste everything
>> starting with the SELECT (probably need to add a trailing ';'.  And
>> then try EXPLAIN EXTENDED.
>
> I have done this, and the query plan looks reasonable, and for
> my environment, the SELECT itself runs very quickly, returning
> (around) 850 rows.
>
> If you need additional assistance, please (first) update the
> statistics for your tables, and then run the EXPLAIN EXTENDED,
> and provide the results.
>
> Gary
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Explain Extended runs under 1 second and returns....

id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra

1	SIMPLE	record	ALL	seriesid,programid,search,type	NULL	NULL	NULL	753	99.73	Using
where

1	SIMPLE	program	ref	PRIMARY,seriesid,id_start_end,program_manualid,previouslyshown,programid,subtitle,description	seriesid	194	mythconverg.record.seriesid	20	100.00	Using
where

1	SIMPLE	channel	eq_ref	PRIMARY,visible	PRIMARY	4	mythconverg.program.chanid	1	100.00	Using
where

Anything obviously wrong here?


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