{
	"explainVersion" : "2",
	"queryPlanner" : {
		"namespace" : "test.xxx",
		"indexFilterSet" : false,
		"parsedQuery" : {
			"a" : {
				"$not" : {
					"$eq" : 2
				}
			}
		},
		"queryHash" : "5AC442E4",
		"planCacheKey" : "B8B60519",
		"optimizationTimeMillis" : 7,
		"optimizedPipeline" : true,
		"maxIndexedOrSolutionsReached" : false,
		"maxIndexedAndSolutionsReached" : false,
		"maxScansToExplodeReached" : false,
		"prunedSimilarIndexes" : false,
		"winningPlan" : {
			"isCached" : true,
			"queryPlan" : {
				"stage" : "PROJECTION_DEFAULT",
				"planNodeId" : 5,
				"transformBy" : {
					"a" : true,
					"_id" : false
				},
				"inputStage" : {
					"stage" : "GROUP",
					"planNodeId" : 4,
					"inputStage" : {
						"stage" : "MATCH",
						"planNodeId" : 3,
						"filter" : {
							"b" : {
								"$not" : {
									"$exists" : true
								}
							}
						},
						"inputStage" : {
							"stage" : "PROJECTION_COVERED",
							"planNodeId" : 2,
							"transformBy" : {
								"b" : true,
								"_id" : false
							},
							"inputStage" : {
								"stage" : "IXSCAN",
								"planNodeId" : 1,
								"keyPattern" : {
									"a" : 1,
									"b" : 1
								},
								"indexName" : "a_1_b_1",
								"isMultiKey" : false,
								"multiKeyPaths" : {
									"a" : [ ],
									"b" : [ ]
								},
								"isUnique" : false,
								"isSparse" : false,
								"isPartial" : false,
								"indexVersion" : 2,
								"direction" : "forward",
								"indexBounds" : {
									"a" : [
										"[MinKey, 2.0)",
										"(2.0, MaxKey]"
									],
									"b" : [
										"[MinKey, MaxKey]"
									]
								}
							}
						}
					}
				}
			},
			"slotBasedPlan" : {
				"slots" : "$$RESULT=s18 env: { s5 = IndexBounds(\"field #0['a']: [MinKey, 2.0), (2.0, MaxKey], field #1['b']: [MinKey, MaxKey]\"), s9 = Nothing, s13 = true }",
				"stages" : "[5] project [s18 = makeBsonObj(MakeObjSpec([a], [a], Closed, RetNothing), null, true, s17)] \n[4] project [s16 = null, s17 = \n    if isNumber(s15) \n    then s15 \n    else doubleDoubleSumFinalize(s15) \n] \n[4] group [] [s15 = sum(1)] spillSlots[s14] mergingExprs[convertSimpleSumToDoubleDoubleSum(s14)] \n[3] filter {!(exists(s1))} \n[1] branch {s13} [s1, s12] \n[s2, s4] [1] ixscan_generic s5 none s4 none none lowPriority [s2 = 1] @\"9d778a81-62ae-44b8-8c8e-a24abcba26d3\" @\"a_1_b_1\" true \n[s3, s6] [1] nlj inner [] [s7, s8] \n    left \n        [1] project [s7 = getField(s10, \"l\"), s8 = getField(s10, \"h\")] \n        [1] unwind s10 s11 s9 false \n        [1] limit 1ll \n        [1] coscan \n    right \n        [1] ixseek s7 s8 none s6 none none [s3 = 1] @\"9d778a81-62ae-44b8-8c8e-a24abcba26d3\" @\"a_1_b_1\" true \n"
			}
		},
		"rejectedPlans" : [ ]
	},
	"executionStats" : {
		"executionSuccess" : true,
		"nReturned" : 0,
		"executionTimeMillis" : 12,
		"totalKeysExamined" : 4,
		"totalDocsExamined" : 0,
		"executionStages" : {
			"stage" : "project",
			"planNodeId" : 5,
			"nReturned" : 0,
			"executionTimeMillisEstimate" : 0,
			"opens" : 1,
			"closes" : 1,
			"saveState" : 0,
			"restoreState" : 0,
			"isEOF" : 1,
			"projections" : {
				"18" : "makeBsonObj(MakeObjSpec([a], [a], Closed, RetNothing), null, true, s17) "
			},
			"inputStage" : {
				"stage" : "project",
				"planNodeId" : 4,
				"nReturned" : 0,
				"executionTimeMillisEstimate" : 0,
				"opens" : 1,
				"closes" : 1,
				"saveState" : 0,
				"restoreState" : 0,
				"isEOF" : 1,
				"projections" : {
					"16" : "null ",
					"17" : "\n    if isNumber(s15) \n    then s15 \n    else doubleDoubleSumFinalize(s15) \n"
				},
				"inputStage" : {
					"stage" : "group",
					"planNodeId" : 4,
					"nReturned" : 0,
					"executionTimeMillisEstimate" : 0,
					"opens" : 1,
					"closes" : 1,
					"saveState" : 0,
					"restoreState" : 0,
					"isEOF" : 1,
					"groupBySlots" : [ ],
					"expressions" : {
						"15" : "sum(1) ",
						"initExprs" : {
							"15" : null
						}
					},
					"mergingExprs" : {
						"14" : "convertSimpleSumToDoubleDoubleSum(s14) "
					},
					"usedDisk" : false,
					"spills" : 0,
					"spilledRecords" : 0,
					"spilledDataStorageSize" : 0,
					"inputStage" : {
						"stage" : "filter",
						"planNodeId" : 3,
						"nReturned" : 0,
						"executionTimeMillisEstimate" : 0,
						"opens" : 1,
						"closes" : 1,
						"saveState" : 0,
						"restoreState" : 0,
						"isEOF" : 1,
						"numTested" : 3,
						"filter" : "!(exists(s1)) ",
						"inputStage" : {
							"stage" : "branch",
							"planNodeId" : 1,
							"nReturned" : 3,
							"executionTimeMillisEstimate" : 0,
							"opens" : 1,
							"closes" : 1,
							"saveState" : 0,
							"restoreState" : 0,
							"isEOF" : 1,
							"numTested" : 1,
							"thenBranchOpens" : 1,
							"thenBranchCloses" : 1,
							"elseBranchOpens" : 0,
							"elseBranchCloses" : 0,
							"filter" : "s13 ",
							"thenSlots" : [
								NumberLong(2),
								NumberLong(4)
							],
							"elseSlots" : [
								NumberLong(3),
								NumberLong(6)
							],
							"outputSlots" : [
								NumberLong(1),
								NumberLong(12)
							],
							"thenStage" : {
								"stage" : "ixscan_generic",
								"planNodeId" : 1,
								"nReturned" : 3,
								"executionTimeMillisEstimate" : 0,
								"opens" : 1,
								"closes" : 1,
								"saveState" : 0,
								"restoreState" : 0,
								"isEOF" : 1,
								"indexName" : "a_1_b_1",
								"keysExamined" : 4,
								"seeks" : 2,
								"numReads" : 5,
								"recordIdSlot" : 4,
								"outputSlots" : [
									NumberLong(2)
								],
								"indexKeysToInclude" : "00000000000000000000000000000010"
							},
							"elseStage" : {
								"stage" : "nlj",
								"planNodeId" : 1,
								"nReturned" : 0,
								"executionTimeMillisEstimate" : 0,
								"opens" : 0,
								"closes" : 0,
								"saveState" : 0,
								"restoreState" : 0,
								"isEOF" : 0,
								"totalDocsExamined" : 0,
								"totalKeysExamined" : 0,
								"collectionScans" : 0,
								"collectionSeeks" : 0,
								"indexScans" : 0,
								"indexSeeks" : 0,
								"indexesUsed" : [
									"a_1_b_1"
								],
								"innerOpens" : 0,
								"innerCloses" : 0,
								"outerProjects" : [ ],
								"outerCorrelated" : [
									NumberLong(7),
									NumberLong(8)
								],
								"outerStage" : {
									"stage" : "project",
									"planNodeId" : 1,
									"nReturned" : 0,
									"executionTimeMillisEstimate" : 0,
									"opens" : 0,
									"closes" : 0,
									"saveState" : 0,
									"restoreState" : 0,
									"isEOF" : 0,
									"projections" : {
										"7" : "getField(s10, \"l\") ",
										"8" : "getField(s10, \"h\") "
									},
									"inputStage" : {
										"stage" : "unwind",
										"planNodeId" : 1,
										"nReturned" : 0,
										"executionTimeMillisEstimate" : 0,
										"opens" : 0,
										"closes" : 0,
										"saveState" : 0,
										"restoreState" : 0,
										"isEOF" : 0,
										"inputSlot" : 9,
										"outSlot" : 10,
										"outIndexSlot" : 11,
										"preserveNullAndEmptyArrays" : 0,
										"inputStage" : {
											"stage" : "limit",
											"planNodeId" : 1,
											"nReturned" : 0,
											"executionTimeMillisEstimate" : 0,
											"opens" : 0,
											"closes" : 0,
											"saveState" : 0,
											"restoreState" : 0,
											"isEOF" : 0,
											"inputStage" : {
												"stage" : "coscan",
												"planNodeId" : 1,
												"nReturned" : 0,
												"executionTimeMillisEstimate" : 0,
												"opens" : 0,
												"closes" : 0,
												"saveState" : 0,
												"restoreState" : 0,
												"isEOF" : 0
											}
										}
									}
								},
								"innerStage" : {
									"stage" : "ixseek",
									"planNodeId" : 1,
									"nReturned" : 0,
									"executionTimeMillisEstimate" : 0,
									"opens" : 0,
									"closes" : 0,
									"saveState" : 0,
									"restoreState" : 0,
									"isEOF" : 0,
									"indexName" : "a_1_b_1",
									"keysExamined" : 0,
									"seeks" : 0,
									"numReads" : 0,
									"recordIdSlot" : 6,
									"outputSlots" : [
										NumberLong(3)
									],
									"indexKeysToInclude" : "00000000000000000000000000000010",
									"seekKeyLow" : "s7 ",
									"seekKeyHigh" : "s8 "
								}
							}
						}
					}
				}
			}
		}
	},
	"command" : {
		"aggregate" : "xxx",
		"pipeline" : [
			{
				"$match" : {
					"a" : {
						"$ne" : 2
					}
				}
			},
			{
				"$match" : {
					"b" : {
						"$exists" : false
					}
				}
			},
			{
				"$count" : "a"
			}
		],
		"cursor" : {
			
		},
		"$db" : "test"
	},
	"serverInfo" : {
		"host" : "ip-10-0-106-40",
		"port" : 27017,
		"version" : "8.0.0-alpha",
		"gitVersion" : "2303b0fec38ba62b6199cd9e83932edd89c61fab"
	},
	"serverParameters" : {
		"internalQueryFacetBufferSizeBytes" : 104857600,
		"internalQueryFacetMaxOutputDocSizeBytes" : 104857600,
		"internalLookupStageIntermediateDocumentMaxSizeBytes" : 104857600,
		"internalDocumentSourceGroupMaxMemoryBytes" : 104857600,
		"internalQueryMaxBlockingSortMemoryUsageBytes" : 104857600,
		"internalQueryProhibitBlockingMergeOnMongoS" : 0,
		"internalQueryMaxAddToSetBytes" : 104857600,
		"internalDocumentSourceSetWindowFieldsMaxMemoryBytes" : 104857600,
		"internalQueryFrameworkControl" : "trySbeEngine"
	},
	"ok" : 1
}