Hello, Arno!
I have faced very poor jDownloads frontend performance.
There is 3,741 files and 754 categories. I have enabled joomla debug console and fetched some data.
There is over 2262 sql queris on jdownloads root page with 9 main categories page loads about 11 sec or more.
21 repeated sql queris.
I have tried different jdownloads version, including latest one on Joomla 3.4.5 and php 5.6.
I guess that it is not a big amount of data, because I have joomgallery with more then 30k of photos and it run's smoothly.
May be you can help find this bottle neck!
Some very slow places:
702.63 ms
SELECT c.*,
CASE WHEN CHAR_LENGTH(c.alias) THEN CONCAT_WS(':', c.id, c.alias) ELSE c.id END as slug,COUNT(files.`file_id`) AS numitems,u.name AS creator,u2.name AS modifier,menu.id AS menu_itemid
FROM kport_jdownloads_categories as c
LEFT JOIN `kport_jdownloads_files` AS files
ON files.`cat_id` = c.id
AND files.published = 1
LEFT JOIN kport_users AS u
on u.id = files.created_id
LEFT JOIN kport_users AS u2
on u2.id = files.modified_id
LEFT JOIN kport_menu AS menu
on menu.link LIKE CONCAT('index.php?option=com_jdownloads&view=category&catid=',c.id,'%')
AND menu.published = 1
AND menu.access IN (1,1,2,7,8,11,21,22,23,24,25,26,28,29,32,34)
WHERE c.access IN (1,1,2,7,8,11,21,22,23,24,25,26,28,29,32,34)
AND c.published = 1
GROUP BY c.id, c.cat_dir, c.cat_dir_parent, c.parent_id, c.lft, c.rgt, c.level, c.title, c.alias, c.description, c.pic, c.access, c.metakey, c.metadesc, c.robots,
c.created_user_id, c.created_time, c.modified_user_id, c.modified_time, c.language, c.notes, c.views, c.params, c.password, c.password_md5, c.ordering, c.published, c.checked_out, c.checked_out_time, c.asset_id
ORDER BY c.title ASC
