+ # Execute query and actually send the matching log rows. Load
+ # the full log records only when we're ready to send them,
+ # though: otherwise, (1) postgres has to build the whole
+ # result set and return it to us before we can send the first
+ # event, and (2) we store lots of records in memory while
+ # waiting to spool them out to the client. Both of these are
+ # troublesome when log records are large (e.g., a collection
+ # update contains both old and new manifest_text).
+ #
+ # Note: find_each implies order('id asc'), which is what we
+ # want.
+ logs.select('logs.id').find_each do |l|