Everything is in the title: When I move 10 images from one gallery to another, it may take 30mn or more.
The database holds around 380.000 images but the tables are properly optimized and each MySQL query such as:
SELECT image_slug FROM wp****_ngg_pictures WHERE image_slug = 'image-961' AND NOT pid = 0 LIMIT 1
takes up to 10 seconds to run.
Thxs for help