Forum OpenACS Q&A: how does maintainer_name in bboard get cached?

I see maintainer_name getting selected in bboard_get_topic_info, and
I understand that the uplevel { } is causing the
set_variables_after_query to set maintainer_name in the calling scope
[e.g. q-and-a.tcl], but I don't understand why this is apparently
getting cached: I changed the query that sets maintainer_name, but
the new result didn't show up until I restarted aolserver.