Client is a University tat has recently started to migrate from Blackboard to moodle.

For various reasons, they have had to set up a category structure that is very wide and flat. So for example they have a top-level category called staff spaces, in which staff work on their courses before (supposedly) moving them into production. The staf spaces category therefore has several hundred sub-categories, one for each staff member, and each of those might have a handfuk of courses.

This seems to be causing severe slowdowns whenever a course is created or deleted. Looking at the database activity when a course is created or deleted, we can see an awful lot of instructions being processed relating to sortorder. On our largest (154 thousand users) site creating a course takes two seconds. On this site the best we have been able to manage after considerable database work, is 25 seconds.

It seems that whenever a course is created or deleted, the sort order of the entire course structure, every category and course, is re-calculated...at least that is what it looks like.

I can't get them to change their category structure...is there any way to put in a workaround so that this huge recalculation is not run every time?

I seem to recall that this might be related to the problem of the sort order field overflowing some months back - perhap sthe fix for that has now caused this problem?

regards

Sean K