| (: XQuery Join Query :) | |
| (: Count max temperature (TMAX) readings for 2000-01-01. :) | |
| count( | |
| let $sensor_collection := "/tmp/1.0_partition_ghcnd_all_xml/sensors" | |
| for $r in collection($sensor_collection)/dataCollection/data | |
| where $r/dataType eq "TMAX" | |
| and fn:year-from-dateTime(xs:dateTime(fn:data($r/date))) eq 2000 | |
| return $r | |
| ) |