Currently we are rejecting any query that asks for a user with over 350,000 edits. This is a simple but probably not great solution, since the edit count isn't necessarily proportional to how expensive the query is (e.g. we also query the logging table). So in some cases, a user with only 100,000 edits could go really slow, and someone with 500,000 edits could actually finish within 15 minutes (our current max query time). Using EXPLAIN, we can go by the estimated row count and abort if it is something unreasonable. This should help us stay within our connection quota, while also allowing people to query for some users with over 350,000 edits.