-
Type:
New Feature
-
Resolution: Fixed
-
Priority:
Major - P3
-
Affects Version/s: None
-
Component/s: None
-
Labels:None
-
Fully Compatible
A query like this:
db.coll.aggregate([
{$group: {
_id: "$meta.a",
mostRecent: {$topN: {
n: 1,
sortBy: {ts: -1},
output: {
ts: "$ts",
measureA: "$measureA",
measureB: "$measureB"
}
}}
}}
])
or
db.coll.aggregate([
{$group: {
_id: "$meta.a",
mostRecent: {$top: {
sortBy: {ts: -1},
output: {
ts: "$ts",
measureA: "$measureA",
measureB: "$measureB"
}
}}
}}
])
Will be rewritten to something like this to get the last point optimization:
db.measurements.aggregate([
{$sort: {"meta.a": 1, "ts": -1}},
{$group: {
_id: "$sensorId”,
ts: {$first: "$ts”},
measureA: {$first: "$measureA"},
measureB: {$first: "$measureB"}
}}
])
- is depended on by
-
-
- Closed
-