{
	"explainVersion" : "2",
	"queryPlanner" : {
		"namespace" : "test.xxx",
		"indexFilterSet" : false,
		"parsedQuery" : {
			"a" : {
				"$not" : {
					"$eq" : 2
				}
			}
		},
		"queryHash" : "8952E15C",
		"planCacheKey" : "FE3D1332",
		"optimizationTimeMillis" : 4,
		"optimizedPipeline" : true,
		"maxIndexedOrSolutionsReached" : false,
		"maxIndexedAndSolutionsReached" : false,
		"maxScansToExplodeReached" : false,
		"prunedSimilarIndexes" : false,
		"winningPlan" : {
			"isCached" : true,
			"queryPlan" : {
				"stage" : "MATCH",
				"planNodeId" : 3,
				"filter" : {
					"b" : {
						"$not" : {
							"$exists" : true
						}
					}
				},
				"inputStage" : {
					"stage" : "FETCH",
					"planNodeId" : 2,
					"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=s22 env: { s2 = IndexBounds(\"field #0['a']: [MinKey, 2.0), (2.0, MaxKey], field #1['b']: [MinKey, MaxKey]\"), s6 = {\"a\" : 1, \"b\" : 1}, s10 = Nothing, s21 = true }",
				"stages" : "[3] filter {!(exists(s24))} \n[2] nlj inner [] [s16, s17, s18, s19, s20] \n    left \n        [1] branch {s21} [s16, s17, s18, s19, s20] \n        [s1, s3, s4, s5, s6] [1] ixscan_generic s2 s5 s1 s3 s4 lowPriority [] @\"9d778a81-62ae-44b8-8c8e-a24abcba26d3\" @\"a_1_b_1\" true \n        [s7, s13, s14, s15, s6] [1] nlj inner [] [s8, s9] \n            left \n                [1] project [s8 = getField(s11, \"l\"), s9 = getField(s11, \"h\")] \n                [1] unwind s11 s12 s10 false \n                [1] limit 1ll \n                [1] coscan \n            right \n                [1] ixseek s8 s9 s15 s7 s13 s14 [] @\"9d778a81-62ae-44b8-8c8e-a24abcba26d3\" @\"a_1_b_1\" true \n    right \n        [2] limit 1ll \n        [2] seek s16 s22 s23 s17 s18 s19 s20 none none [s24 = b] @\"9d778a81-62ae-44b8-8c8e-a24abcba26d3\" true false \n"
			}
		},
		"rejectedPlans" : [ ]
	},
	"executionStats" : {
		"executionSuccess" : true,
		"nReturned" : 1,
		"executionTimeMillis" : 11,
		"totalKeysExamined" : 4,
		"totalDocsExamined" : 3,
		"executionStages" : {
			"stage" : "filter",
			"planNodeId" : 3,
			"nReturned" : 1,
			"executionTimeMillisEstimate" : 0,
			"opens" : 1,
			"closes" : 1,
			"saveState" : 0,
			"restoreState" : 0,
			"isEOF" : 1,
			"numTested" : 3,
			"filter" : "!(exists(s24)) ",
			"inputStage" : {
				"stage" : "nlj",
				"planNodeId" : 2,
				"nReturned" : 3,
				"executionTimeMillisEstimate" : 0,
				"opens" : 1,
				"closes" : 1,
				"saveState" : 0,
				"restoreState" : 0,
				"isEOF" : 1,
				"totalDocsExamined" : 3,
				"totalKeysExamined" : 4,
				"collectionScans" : 0,
				"collectionSeeks" : 3,
				"indexScans" : 0,
				"indexSeeks" : 1,
				"indexesUsed" : [
					"a_1_b_1",
					"a_1_b_1"
				],
				"innerOpens" : 3,
				"innerCloses" : 1,
				"outerProjects" : [ ],
				"outerCorrelated" : [
					NumberLong(16),
					NumberLong(17),
					NumberLong(18),
					NumberLong(19),
					NumberLong(20)
				],
				"outerStage" : {
					"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" : "s21 ",
					"thenSlots" : [
						NumberLong(1),
						NumberLong(3),
						NumberLong(4),
						NumberLong(5),
						NumberLong(6)
					],
					"elseSlots" : [
						NumberLong(7),
						NumberLong(13),
						NumberLong(14),
						NumberLong(15),
						NumberLong(6)
					],
					"outputSlots" : [
						NumberLong(16),
						NumberLong(17),
						NumberLong(18),
						NumberLong(19),
						NumberLong(20)
					],
					"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,
						"indexKeySlot" : 5,
						"recordIdSlot" : 1,
						"snapshotIdSlot" : 3,
						"indexIdentSlot" : 4,
						"outputSlots" : [ ],
						"indexKeysToInclude" : "00000000000000000000000000000000"
					},
					"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(8),
							NumberLong(9)
						],
						"outerStage" : {
							"stage" : "project",
							"planNodeId" : 1,
							"nReturned" : 0,
							"executionTimeMillisEstimate" : 0,
							"opens" : 0,
							"closes" : 0,
							"saveState" : 0,
							"restoreState" : 0,
							"isEOF" : 0,
							"projections" : {
								"8" : "getField(s11, \"l\") ",
								"9" : "getField(s11, \"h\") "
							},
							"inputStage" : {
								"stage" : "unwind",
								"planNodeId" : 1,
								"nReturned" : 0,
								"executionTimeMillisEstimate" : 0,
								"opens" : 0,
								"closes" : 0,
								"saveState" : 0,
								"restoreState" : 0,
								"isEOF" : 0,
								"inputSlot" : 10,
								"outSlot" : 11,
								"outIndexSlot" : 12,
								"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,
							"indexKeySlot" : 15,
							"recordIdSlot" : 7,
							"snapshotIdSlot" : 13,
							"indexIdentSlot" : 14,
							"outputSlots" : [ ],
							"indexKeysToInclude" : "00000000000000000000000000000000",
							"seekKeyLow" : "s8 ",
							"seekKeyHigh" : "s9 "
						}
					}
				},
				"innerStage" : {
					"stage" : "limit",
					"planNodeId" : 2,
					"nReturned" : 3,
					"executionTimeMillisEstimate" : 0,
					"opens" : 3,
					"closes" : 1,
					"saveState" : 0,
					"restoreState" : 0,
					"isEOF" : 1,
					"limit" : 1,
					"inputStage" : {
						"stage" : "seek",
						"planNodeId" : 2,
						"nReturned" : 3,
						"executionTimeMillisEstimate" : 0,
						"opens" : 3,
						"closes" : 1,
						"saveState" : 0,
						"restoreState" : 0,
						"isEOF" : 0,
						"numReads" : 3,
						"recordSlot" : 22,
						"recordIdSlot" : 23,
						"seekRecordIdSlot" : 16,
						"snapshotIdSlot" : 17,
						"indexIdentSlot" : 18,
						"indexKeySlot" : 19,
						"indexKeyPatternSlot" : 20,
						"scanFieldNames" : [
							"b"
						],
						"scanFieldSlots" : [
							NumberLong(24)
						]
					}
				}
			}
		}
	},
	"command" : {
		"aggregate" : "xxx",
		"pipeline" : [
			{
				"$match" : {
					"a" : {
						"$ne" : 2
					}
				}
			},
			{
				"$match" : {
					"b" : {
						"$exists" : false
					}
				}
			}
		],
		"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
}