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Type:
Task
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Resolution: Gone away
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Priority:
Major - P3
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None
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Affects Version/s: None
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Component/s: None
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Labels:
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Query Execution
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2
The following workload has regressed:
| union_with | UnionWith.UnionWithThreeCollNestedNoOverlap | -12.69541889 |
Here's the query:
[{$unionWith: { coll: "Collection1", pipeline: [{$set: {integer: "$integer"}}, {$unionWith: {coll: "Collection2", pipeline: [{$set: {integer: "$integer"}}]}}]}}]
And the explain:
> db.coll.explain().aggregate( [{$unionWith: { coll: "Collection1", pipeline: [{$set: {integer: "$integer"}}, {$unionWith: {coll: "Collection2", pipeline: [{$set: {integer: "$integer"}}]}}]}}] )
{
"explainVersion" : "2",
"stages" : [
{
"$cursor" : {
"queryPlanner" : {
"namespace" : "db.coll",
"indexFilterSet" : false,
"parsedQuery" : { },
"queryHash" : "2A5DDA38",
"planCacheKey" : "7B89F552",
"maxIndexedOrSolutionsReached" : false,
"maxIndexedAndSolutionsReached" : false,
"maxScansToExplodeReached" : false,
"winningPlan" : {
"queryPlan" : {
"stage" : "COLLSCAN",
"planNodeId" : 1,
"filter" : { },
"direction" : "forward"
},
"slotBasedPlan" : {
"slots" : "$$RESULT=s4 env: { s3 = 1673294711490 (NOW), s1 = TimeZoneDatabase(Asia/Jayapura...Australia/Hobart) (timeZoneDB), s2 = Nothing (SEARCH_META) }",
"stages" : "[1] scan s4 s5 none none none none [] @\"8921938a-f5dc-4556-896b-1b9381e9f125\" true false "
}
},
"rejectedPlans" : [ ]
}
}
},
{
"$unionWith" : {
"coll" : "Collection1",
"pipeline" : [
{
"$cursor" : {
"queryPlanner" : {
"namespace" : "db.Collection1",
"indexFilterSet" : false,
"parsedQuery" : { },
"queryHash" : "2A5DDA38",
"planCacheKey" : "6E411424",
"maxIndexedOrSolutionsReached" : false,
"maxIndexedAndSolutionsReached" : false,
"maxScansToExplodeReached" : false,
"winningPlan" : {
"queryPlan" : {
"stage" : "COLLSCAN",
"planNodeId" : 1,
"filter" : { },
"direction" : "forward"
},
"slotBasedPlan" : {
"slots" : "$$RESULT=s4 env: { s3 = 1673294711490 (NOW), s1 = TimeZoneDatabase(Asia/Jayapura...Australia/Hobart) (timeZoneDB), s2 = Nothing (SEARCH_META) }",
"stages" : "[1] scan s4 s5 none none none none [] @\"ebd072cd-19b2-4f47-8cdf-bcbccde6942c\" true false "
}
},
"rejectedPlans" : [ ]
}
}
},
{
"$set" : {
"integer" : "$integer"
}
},
{
"$unionWith" : {
"coll" : "Collection2",
"pipeline" : [
{
"$cursor" : {
"queryPlanner" : {
"namespace" : "db.Collection2",
"indexFilterSet" : false,
"parsedQuery" : { },
"queryHash" : "2A5DDA38",
"planCacheKey" : "468B32E6",
"maxIndexedOrSolutionsReached" : false,
"maxIndexedAndSolutionsReached" : false,
"maxScansToExplodeReached" : false,
"winningPlan" : {
"queryPlan" : {
"stage" : "COLLSCAN",
"planNodeId" : 1,
"filter" : { },
"direction" : "forward"
},
"slotBasedPlan" : {
"slots" : "$$RESULT=s4 env: { s1 = TimeZoneDatabase(Asia/Jayapura...Australia/Hobart) (timeZoneDB), s2 = Nothing (SEARCH_META), s3 = 1673294711490 (NOW) }",
"stages" : "[1] scan s4 s5 none none none none [] @\"7744af4c-2b82-4ec9-8ed0-07a8ea62f0ef\" true false "
}
},
"rejectedPlans" : [ ]
}
}
},
{
"$set" : {
"integer" : "$integer"
}
}
]
}
}
]
}
}
],
"serverInfo" : {
"host" : "ip-10-122-15-159",
"port" : 27017,
"version" : "6.3.0-alpha-833-g14311b5",
"gitVersion" : "14311b5b2491c609c7d1e08d13913410c2022afc"
},
"serverParameters" : {
"internalQueryFacetBufferSizeBytes" : 104857600,
"internalQueryFacetMaxOutputDocSizeBytes" : 104857600,
"internalLookupStageIntermediateDocumentMaxSizeBytes" : 104857600,
"internalDocumentSourceGroupMaxMemoryBytes" : 104857600,
"internalQueryMaxBlockingSortMemoryUsageBytes" : 104857600,
"internalQueryProhibitBlockingMergeOnMongoS" : 0,
"internalQueryMaxAddToSetBytes" : 104857600,
"internalDocumentSourceSetWindowFieldsMaxMemoryBytes" : 104857600,
"internalQueryFrameworkControl" : "tryBonsai"
},
"command" : {
"aggregate" : "coll",
"pipeline" : [
{
"$unionWith" : {
"coll" : "Collection1",
"pipeline" : [
{
"$set" : {
"integer" : "$integer"
}
},
{
"$unionWith" : {
"coll" : "Collection2",
"pipeline" : [
{
"$set" : {
"integer" : "$integer"
}
}
]
}
}
]
}
}
],
"explain" : true,
"cursor" : { },
"lsid" : {
"id" : UUID("c5fa033f-f963-4fb1-b709-75c24ea632d4")
},
"$db" : "db"
},
"ok" : 1
}
Ultimately it is 3 nested collections with some projections in the mix.