Which time unit does graphdb's onto:measure uses?

Question

The GraphDB docs states that if i want collect the execution time of a query a should use onto:measure like in the example bellow. However it doesn ́t states which time unit it returns neither if the total execution time is the sum of the indivual time of each collection. Does anyone knows this answers and where can i learn more about onto:measure in general?

PREFIX onto: <http://www.ontotext.com/> 
PREFIX gtfs: <http://vocab.gtfs.org/terms#> 
PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#> 
SELECT * FROM onto:measure{ 
?shape a gtfs:Shape . 
?shape gtfs:shapePoint ?shapePoint. 
?shapePoint geo:lat ?shape_pt_lat . 
?shapePoint geo:long ?shape_pt_lon . 
?shapePoint gtfs:pointSequence ?shape_pt_sequence . 
}

PREFIX gtfs: <http://vocab.gtfs.org/terms#>
PREFIX geo: <http://www.w3.org/2003/01/geo/wgs84_pos#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
SELECT ?shape ?shapePoint ?shape_pt_lat ?shape_pt_lon ?shape_pt_sequence
{
 
 { # ----- Begin optimization group 1 -----
 
 ?shape rdf:type gtfs:Shape . # Collection size: 956 Predicate collection size: 1,462,787 Unique subjects: 1,462,619 Unique objects: 23 Current complexity: 956
 # EXECUTION: (count:956 totalTime:1 minTime:0 maxTime:0 ownTime:0 externalTime:0)
 ?shape gtfs:shapePoint ?shapePoint . # Collection size: 354,750 Predicate collection size: 354,750 Unique subjects: 956 Unique objects: 354,750 Current complexity: 354,750
 # EXECUTION: (count:354750 totalTime:203 minTime:0 maxTime:0 ownTime:62 externalTime:140)
 ?shapePoint geo:lat ?shape_pt_lat . # Collection size: 362,156 Predicate collection size: 362,156 Unique subjects: 362,156 Unique objects: 29,254 Current complexity: 354,750
 # EXECUTION: (count:354750 totalTime:183 minTime:0 maxTime:0 ownTime:61 externalTime:121)
 ?shapePoint geo:long ?shape_pt_lon . # Collection size: 362,156 Predicate collection size: 362,156 Unique subjects: 362,156 Unique objects: 40,138 Current complexity: 354,750
 # EXECUTION: (count:354750 totalTime:207 minTime:0 maxTime:1 ownTime:62 externalTime:145)
 ?shapePoint gtfs:pointSequence ?shape_pt_sequence . # Collection size: 354,750 Predicate collection size: 354,750 Unique subjects: 354,750 Unique objects: 1,087 Current complexity: 354,750
 # EXECUTION: (count:354750 totalTime:215 minTime:0 maxTime:1 ownTime:64 externalTime:150)
 
 } # ----- End optimization group 1 -----
 # ESTIMATED NUMBER OF ITERATIONS: 354,750
 
}
# NOTE: Optimization groups are evaluated one after another exactly in the given order.
# If there are too many optimization groups consisting of a single statement pattern,
# then one should try to relocate the following clauses by hand:
# VALUES, BIND, OPTIONAL, property paths with '*' and/or '+' (the latter can be also surrounded with brackets).
# Sub-SELECTs will always be evaluated first.

• Stilyana Kaleeva: In GraphDB, onto:measurement values are represented in milliseconds. When monitoring an event, the overall duration is determined by adding together all the timing intervals noted for that event. In cases of nested measurements (meaning events within events), the system computes a net execution time by deducting the duration of those nested events from the overall total. This helps isolate how much time was actually spent in the top-level operation itself.