The reading aggregation functions like solardatm.find_datm_diff_near_rows() use solardatm.find_datm_around() to locate nearby rows within a datum stream that also include accumulating properties. This is necessary to support datum streams with intermittent accumulating property values. Some streams do not even have accumualting properties, however. The query must then search for the maximum tolerance allowed (currently 1 year) for a row with an accumulating property value that no rows will have. Improve the query speed on such streams, by avoiding the large row scan for rows we know will not exist.