MARK CALLAGHAN writes:
>> Another is my_hash_sort_simple(). This is not a regression, but Oprofile
>> shows
>> we spend 10% of total time in this function.
>
> Does this do utf aware compares or memcmp?
This one uses collations - so not memcmp. It is used for SELECT DISTINCT and
GROUP BY. This
>
> But my main point is to present these results, to show that we have a very
> useful tool to pin-point these performance issues, and to start discussion in
> more detail (and I have plenty more of those).
Nice work.
>
> Another is my_hash_sort_simple(). This is not a regression, but Oprofile s
Kristian Nielsen writes:
Some additional info found from analysis so far:
> 39k mysql_select
This seems mostly caused by expensive JOIN constructor, as Wlad mentioned.
> 16k JOIN::choose_subquery_plan
This is caused by unnecessary C++ object construction (thanks,
Timour!). Moving
o: maria-developers@lists.launchpad.net
> Subject: [Maria-developers] Analysing MariaDB 5.5 sysbench performance
> regression
>
> I have been analysing the performance difference between MariaDB 5.5.21
> and
> MySQL 5.5.21 using oltp.lua in sysbench 0.5. It turns out that MySQ
I have been analysing the performance difference between MariaDB 5.5.21 and
MySQL 5.5.21 using oltp.lua in sysbench 0.5. It turns out that MySQL has about
8% higher tps in this benchmark when running CPU bound. (See below for links to
blog posts that started this).
I took the base sysbench run and
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