Then I tried query-level triggers that just take a diff of a database view and

relation_tuple

, and update

relation_tuple

to be in sync each time a query ran. This worked but it was slow; I didn't know how slow, however, until we tried to run it on real data this week. The naive trigger timed out; our DB guy was able to tune it to 5 seconds per update, but 5 seconds is still way too slow.