Most aggregators are coded to ignore missing columns (sum treats them as zeroes, min treats them as positive infinity, etc). Math expressions, however, fail with a "no binding found" message. A quick fix would be to have them return 0L for missing columns, but IMO it'd be better to allow expressions to be "nullable" and have the aggregators deal with that as appropriate. The goes is to make min(MISSING, 1, 2) = 1 instead of an exception or zero.
Most aggregators are coded to ignore missing columns (sum treats them as zeroes, min treats them as positive infinity, etc). Math expressions, however, fail with a "no binding found" message. A quick fix would be to have them return
0Lfor missing columns, but IMO it'd be better to allow expressions to be "nullable" and have the aggregators deal with that as appropriate. The goes is to makemin(MISSING, 1, 2) = 1instead of an exception or zero.