[mythtv-users] Bad mysql performance -- huge oldrecorded -- joins without index

Simon Hobson linux at thehobsons.co.uk
Wed Jun 8 13:10:18 UTC 2016


Håkon Alstadheim <hakon at alstadheim.priv.no> wrote:

> Mysqltuner complains about "Joins performed without indexes", but I do
> not know enough mysql to start looking into that. Any hints ?

Well that's a code thing - so without altering the code there's nothing you can do to optimise that aspect.
But there is great scope for just tweaking the memory footprint for MySQL. Up to some point, basically the more RAM you allow it to use, the better it will perform - the defaults are "fairly conservative".

Overall your values look reasonable - I assume you've already been tweaking them. But this one does stand out : "Query cache is disabled" - I assume that's not normal.



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