People may have noticed that the front page of london.openguides.org has been terribly slow for a while. I'm sorry it's taken me so long to have a think and sort this out. I have implemented a fix that will be in OpenGuides 0.31, and it's speeded up loads. Earle: if you upgrade to 0.30 then this fix will need reapplying. Patch is attached.
Essentially the problem is that the metadata_wasnt option of ->list_recent_changes is terribly inefficient - I implemented it in a hurry and haven't revisited it since. I've swapped over to filtering on metadata_was, which is much faster.
Kake