Comment 6 for bug 597838

The "slow load" issue is a cache locality problem. The following
computation:

 >>> [y for x, y in root.tags._tagid_to_obj.items()
 ... if y.community == 'nonesuch']
 []

takes many seconds (likely the 30-40 originally reported) on a cold ZODB
cache, but is nearly instantaneous on a hot cache.

Fixing this correctly likely involves generating sample data for profiling..

Here is some data, drawn from production:

 >>> len(root.tags._tagid_to_obj)
 37666
 >>> len(root.tags._item_to_tagids)
 7435
 >>> len(root.tags._name_to_tagids)
 4353
 >>> len(root.tags._user_to_tagids)
 500
 >>> len(set([y.community for x, y in root.tags._tagid_to_obj.items()]))
 384