Joomla 1.6 menu problem in mysql (execution time < 10 min)

I found that code in the bottom executes more than 10 minutes on my server. The server itself is quite good and I cannot find any suitable explanation for that. I am using Joomla 1.6.3 the data is migrated from Joomla 1.5.23 using jUpgrade and MySQL client version is 5.1.45.

SELECT a.*,COUNT(DISTINCT m1.id) AS count_published,COUNT(DISTINCT m2.id) AS count_unpublished,COUNT(DISTINCT m3.id) AS count_trashed
FROM `j16_menu_types` AS a
LEFT JOIN `j16_menu` AS m1 ON m1.menutype = a.menutype AND m1.published = 1
LEFT JOIN `j16_menu` AS m2 ON m2.menutype = a.menutype AND m2.published = 0
LEFT JOIN `j16_menu` AS m3 ON m3.menutype = a.menutype AND m3.published = -2
GROUP BY a.id
ORDER BY a.id asc;

I would be very pleased if someone could help me since I am in big trouble :)

P.s. I have downloaded db a开发者_如何学Gond checked it on my computer - still the same, execution time is terrible. Is there any way to solve this problem? Or maybe to remove this sql part without significant changes in administration of joomla? Well it was done quite faster on my PC but still the result is far from one which would satisfy my.

EDIT Well, I've found a reported bug of this problem. http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=24868

And the solution is:

CREATE INDEX idx_menu_published ON j16_menu (published);

However, I am not sure how this will affect administration. I there is anyone who could briefly tell how this part works and should I edit Joomla core code or just use the above code on mysql once. I am wondering if I should index table everytime when I edit menu.

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A database / table Index is just a kind of yellow pages if you don't mind the comparison. It updates automatically. If this Index fixes your problem there is nothing else you need to do or do again. You can't break anything either - so just give it a try.