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Resolution: Unresolved
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Priority:
Major - P3
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Affects Version/s: None
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Component/s: None
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Query Integration
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As part of adding write metrics like 'nUpdated', we are wondering about changing the output schema of $queryStats. Going from something like this (current structure):
{
key: { /* same */ },
keyHash: 'dsoJ+LHAru0z6MJ1/IygJnnLTrlpVYYmPnlmNZbZrLI=',
queryShapeHash: "uxMLCvpiJ5N/IRqt4c28/0A8F01C8AA16CA805FF5C1A5737535F97E40C2A90CE91A82CCB7A74C7CCB9C48",
"metrics" : {
"lastExecutionMicros" : NumberLong(903),
"execCount" : NumberLong(1),
"totalExecMicros" : {
"sum" : NumberLong(903),
"max" : NumberLong(903),
"min" : NumberLong(903),
"sumOfSquares" : NumberDecimal("815409")
},
"firstResponseExecMicros" : {
"sum" : NumberLong(903),
"max" : NumberLong(903),
"min" : NumberLong(903),
"sumOfSquares" : NumberDecimal("815409")
},
"docsReturned" : {
"sum" : NumberLong(1),
"max" : NumberLong(1),
"min" : NumberLong(1),
"sumOfSquares" : NumberDecimal("1")
},
"keysExamined" : {
"sum" : NumberLong(0),
"max" : NumberLong(0),
"min" : NumberLong(0),
"sumOfSquares" : NumberDecimal("0")
},
"docsExamined" : {
"sum" : NumberLong(0),
"max" : NumberLong(0),
"min" : NumberLong(0),
"sumOfSquares" : NumberDecimal("0")
},
"bytesRead" : {
"sum" : NumberLong(0),
"max" : NumberLong(0),
"min" : NumberLong(0),
"sumOfSquares" : NumberDecimal("0")
},
"readTimeMicros" : {
"sum" : NumberLong(0),
"max" : NumberLong(0),
"min" : NumberLong(0),
"sumOfSquares" : NumberDecimal("0")
},
"workingTimeMillis" : {
"sum" : NumberLong(0),
"max" : NumberLong(0),
"min" : NumberLong(0),
"sumOfSquares" : NumberDecimal("0")
},
"cpuNanos" : {
"sum" : NumberLong(914563),
"max" : NumberLong(914563),
"min" : NumberLong(914563),
"sumOfSquares" : NumberDecimal("836425480969")
},
"delinquentAcquisitions" : {
"sum" : NumberLong(0),
"max" : NumberLong(0),
"min" : NumberLong(0),
"sumOfSquares" : NumberDecimal("0")
},
"totalAcquisitionDelinquencyMillis" : {
"sum" : NumberLong(0),
"max" : NumberLong(0),
"min" : NumberLong(0),
"sumOfSquares" : NumberDecimal("0")
},
"maxAcquisitionDelinquencyMillis" : {
"sum" : NumberLong(0),
"max" : NumberLong(0),
"min" : NumberLong(0),
"sumOfSquares" : NumberDecimal("0")
},
"hasSortStage" : {
"true" : NumberLong(0),
"false" : NumberLong(1)
},
"usedDisk" : {
"true" : NumberLong(0),
"false" : NumberLong(1)
},
"fromMultiPlanner" : {
"true" : NumberLong(0),
"false" : NumberLong(1)
},
"fromPlanCache" : {
"true" : NumberLong(0),
"false" : NumberLong(1)
},
"firstSeenTimestamp" : ISODate("2025-08-26T15:11:26.307Z"),
"latestSeenTimestamp" : ISODate("2025-08-26T15:11:26.307Z")
},
"asOf" : ISODate("2025-08-26T15:11:29.112Z")
}
to something more like this:
{
key: { /* same */ },
keyHash: 'dsoJ+LHAru0z6MJ1/IygJnnLTrlpVYYmPnlmNZbZrLI=',
queryShapeHash: "uxMLCvpiJ5N/IRqt4c28/0A8F01C8AA16CA805FF5C1A5737535F97E40C2A90CE91A82CCB7A74C7CCB9C48",
"metrics" : {
"lastExecutionMicros" : NumberLong(903),
"execCount" : NumberLong(1),
"totalExecMicros" : {
"sum" : NumberLong(903),
"max" : NumberLong(903),
"min" : NumberLong(903),
"sumOfSquares" : NumberDecimal("815409")
},
"workingTimeMillis" : {
"sum" : NumberLong(0),
"max" : NumberLong(0),
"min" : NumberLong(0),
"sumOfSquares" : NumberDecimal("0")
},
"cpuNanos" : {
"sum" : NumberLong(914563),
"max" : NumberLong(914563),
"min" : NumberLong(914563),
"sumOfSquares" : NumberDecimal("836425480969")
},
"queryExec": {
"firstResponseExecMicros" : {
"sum" : NumberLong(903),
"max" : NumberLong(903),
"min" : NumberLong(903),
"sumOfSquares" : NumberDecimal("815409")
},
"docsReturned" : {
"sum" : NumberLong(1),
"max" : NumberLong(1),
"min" : NumberLong(1),
"sumOfSquares" : NumberDecimal("1")
},
"keysExamined" : {
"sum" : NumberLong(0),
"max" : NumberLong(0),
"min" : NumberLong(0),
"sumOfSquares" : NumberDecimal("0")
},
"docsExamined" : {
"sum" : NumberLong(0),
"max" : NumberLong(0),
"min" : NumberLong(0),
"sumOfSquares" : NumberDecimal("0")
},
"bytesRead" : {
"sum" : NumberLong(0),
"max" : NumberLong(0),
"min" : NumberLong(0),
"sumOfSquares" : NumberDecimal("0")
},
"readTimeMicros" : {
"sum" : NumberLong(0),
"max" : NumberLong(0),
"min" : NumberLong(0),
"sumOfSquares" : NumberDecimal("0")
},
"delinquentAcquisitions" : {
"sum" : NumberLong(0),
"max" : NumberLong(0),
"min" : NumberLong(0),
"sumOfSquares" : NumberDecimal("0")
},
"totalAcquisitionDelinquencyMillis" : {
"sum" : NumberLong(0),
"max" : NumberLong(0),
"min" : NumberLong(0),
"sumOfSquares" : NumberDecimal("0")
},
"maxAcquisitionDelinquencyMillis" : {
"sum" : NumberLong(0),
"max" : NumberLong(0),
"min" : NumberLong(0),
"sumOfSquares" : NumberDecimal("0")
},
},
"queryPlanner": {
"hasSortStage" : {
"true" : NumberLong(0),
"false" : NumberLong(1)
},
"usedDisk" : {
"true" : NumberLong(0),
"false" : NumberLong(1)
},
"fromMultiPlanner" : {
"true" : NumberLong(0),
"false" : NumberLong(1)
},
"fromPlanCache" : {
"true" : NumberLong(0),
"false" : NumberLong(1)
},
},
// NEW!
"writes": {
"nMatched" : {
"sum" : NumberLong(0),
"max" : NumberLong(0),
"min" : NumberLong(0),
"sumOfSquares" : NumberDecimal("0")
},
...
}
"firstSeenTimestamp" : ISODate("2025-08-26T15:11:26.307Z"),
"latestSeenTimestamp" : ISODate("2025-08-26T15:11:26.307Z")
},
"asOf" : ISODate("2025-08-26T15:11:29.112Z")
}
I think this would be a breaking change for existing tools such as the data warehouse pipeline and the query stats insights atlas page we're working on. However, I think the workaround is easy. I believe the workaround could be as simple as adding a $project stage to go back to the old format if you want that.
he motivation here is simply better organization of the metrics. When we began there were fewer than 10. An upcoming project will add 5 or so more, and in the meantime there have already been maybe 8 more. The growing list of top-level fields is hard to understand from a documentation and human perspective.