Executing against a sharded cluster with 2 shards: mongos> db.adminCommand({enableSharding: "test" }) { "ok" : 1, "$clusterTime" : { "clusterTime" : Timestamp(1515170563, 7), "signature" : { "hash" : BinData(0, "AAAAAAAAAAAAAAAAAAAAAAAAAAA=" ), "keyId" : NumberLong(0) } }, "operationTime" : Timestamp(1515170563, 7) } mongos> db.adminCommand({shardCollection: "test.foo" , key: {_id: "hashed" }, initialChunks: 4}) { "collectionsharded" : "test.foo" , "collectionUUID" : UUID( "2651991b-cf82-43f6-bd70-8c26d35f2b7f" ), "ok" : 1, "$clusterTime" : { "clusterTime" : Timestamp(1515170584, 14), "signature" : { "hash" : BinData(0, "AAAAAAAAAAAAAAAAAAAAAAAAAAA=" ), "keyId" : NumberLong(0) } }, "operationTime" : Timestamp(1515170584, 6) } mongos> db.foo.insert([{_id: 0}, {_id: 1}, {_id: 2}, {_id: 3}, {_id: 4}, {_id: 5}, {_id: 6}, {_id: 7}, {_id: 8}]) BulkWriteResult({ "writeErrors" : [ ], "writeConcernErrors" : [ ], "nInserted" : 9, "nUpserted" : 0, "nMatched" : 0, "nModified" : 0, "nRemoved" : 0, "upserted" : [ ] }) mongos> sh.status() --- Sharding Status --- sharding version: { "_id" : 1, "minCompatibleVersion" : 5, "currentVersion" : 6, "clusterId" : ObjectId( "5a4faaf8e6190e5786912ddd" ) } shards: { "_id" : "shard0000" , "host" : "franklinia:20000" , "state" : 1 } { "_id" : "shard0001" , "host" : "franklinia:20001" , "state" : 1 } active mongoses: "0.0.0" : 1 autosplit: Currently enabled: no balancer: Currently enabled: no Currently running: no Failed balancer rounds in last 5 attempts: 0 Migration Results for the last 24 hours: 1 : Success databases: { "_id" : "config" , "primary" : "config" , "partitioned" : true } config.system.sessions shard key: { "_id" : 1 } unique: false balancing: true chunks: shard0000 1 { "_id" : { "$minKey" : 1 } } -->> { "_id" : { "$maxKey" : 1 } } on : shard0000 Timestamp(1, 0) { "_id" : "test" , "primary" : "shard0001" , "partitioned" : true } test.foo shard key: { "_id" : "hashed" } unique: false balancing: true chunks: shard0000 2 shard0001 2 { "_id" : { "$minKey" : 1 } } -->> { "_id" : NumberLong( "-4611686018427387902" ) } on : shard0000 Timestamp(2, 2) { "_id" : NumberLong( "-4611686018427387902" ) } -->> { "_id" : NumberLong(0) } on : shard0000 Timestamp(2, 3) { "_id" : NumberLong(0) } -->> { "_id" : NumberLong( "4611686018427387902" ) } on : shard0001 Timestamp(2, 4) { "_id" : NumberLong( "4611686018427387902" ) } -->> { "_id" : { "$maxKey" : 1 } } on : shard0001 Timestamp(2, 5) mongos> db.foo.find({_id: {$gte: 0, $lte: 8}}).limit(3) { "_id" : 3 } { "_id" : 6 } { "_id" : 8 } mongos> db.foo.explain( true ).find({_id: {$gte: 0, $lte: 8}}).limit(3) { "queryPlanner" : { "mongosPlannerVersion" : 1, "winningPlan" : { "stage" : "SHARD_MERGE" , "shards" : [ { "shardName" : "shard0001" , "connectionString" : "franklinia:20001" , "serverInfo" : { "host" : "franklinia" , "port" : 20001, "version" : "0.0.0" , "gitVersion" : "unknown" }, "plannerVersion" : 1, "namespace" : "test.foo" , "indexFilterSet" : false , "parsedQuery" : { "$and" : [ { "_id" : { "$lte" : 8 } }, { "_id" : { "$gte" : 0 } } ] }, "winningPlan" : { "stage" : "LIMIT" , "limitAmount" : 3, "inputStage" : { "stage" : "FETCH" , "inputStage" : { "stage" : "SHARDING_FILTER" , "inputStage" : { "stage" : "IXSCAN" , "keyPattern" : { "_id" : 1 }, "indexName" : "_id_" , "isMultiKey" : false , "multiKeyPaths" : { "_id" : [ ] }, "isUnique" : true , "isSparse" : false , "isPartial" : false , "indexVersion" : 2, "direction" : "forward" , "indexBounds" : { "_id" : [ "[0.0, 8.0]" ] } } } } }, "rejectedPlans" : [ ] }, { "shardName" : "shard0000" , "connectionString" : "franklinia:20000" , "serverInfo" : { "host" : "franklinia" , "port" : 20000, "version" : "0.0.0" , "gitVersion" : "unknown" }, "plannerVersion" : 1, "namespace" : "test.foo" , "indexFilterSet" : false , "parsedQuery" : { "$and" : [ { "_id" : { "$lte" : 8 } }, { "_id" : { "$gte" : 0 } } ] }, "winningPlan" : { "stage" : "LIMIT" , "limitAmount" : 3, "inputStage" : { "stage" : "FETCH" , "inputStage" : { "stage" : "SHARDING_FILTER" , "inputStage" : { "stage" : "IXSCAN" , "keyPattern" : { "_id" : 1 }, "indexName" : "_id_" , "isMultiKey" : false , "multiKeyPaths" : { "_id" : [ ] }, "isUnique" : true , "isSparse" : false , "isPartial" : false , "indexVersion" : 2, "direction" : "forward" , "indexBounds" : { "_id" : [ "[0.0, 8.0]" ] } } } } }, "rejectedPlans" : [ ] } ] } }, "executionStats" : { "nReturned" : 6, "executionTimeMillis" : 2, "totalKeysExamined" : 6, "totalDocsExamined" : 6, "executionStages" : { "stage" : "SHARD_MERGE" , "nReturned" : 6, "executionTimeMillis" : 2, "totalKeysExamined" : 6, "totalDocsExamined" : 6, "totalChildMillis" : NumberLong(0), "shards" : [ { "shardName" : "shard0001" , "executionSuccess" : true , "executionStages" : { "stage" : "LIMIT" , "nReturned" : 3, "executionTimeMillisEstimate" : 0, "works" : 4, "advanced" : 3, "needTime" : 0, "needYield" : 0, "saveState" : 0, "restoreState" : 0, "isEOF" : 1, "invalidates" : 0, "limitAmount" : 3, "inputStage" : { "stage" : "FETCH" , "nReturned" : 3, "executionTimeMillisEstimate" : 0, "works" : 3, "advanced" : 3, "needTime" : 0, "needYield" : 0, "saveState" : 0, "restoreState" : 0, "isEOF" : 0, "invalidates" : 0, "docsExamined" : 3, "alreadyHasObj" : 0, "inputStage" : { "stage" : "SHARDING_FILTER" , "nReturned" : 3, "executionTimeMillisEstimate" : 0, "works" : 3, "advanced" : 3, "needTime" : 0, "needYield" : 0, "saveState" : 0, "restoreState" : 0, "isEOF" : 0, "invalidates" : 0, "chunkSkips" : 0, "inputStage" : { "stage" : "IXSCAN" , "nReturned" : 3, "executionTimeMillisEstimate" : 0, "works" : 3, "advanced" : 3, "needTime" : 0, "needYield" : 0, "saveState" : 0, "restoreState" : 0, "isEOF" : 0, "invalidates" : 0, "keyPattern" : { "_id" : 1 }, "indexName" : "_id_" , "isMultiKey" : false , "multiKeyPaths" : { "_id" : [ ] }, "isUnique" : true , "isSparse" : false , "isPartial" : false , "indexVersion" : 2, "direction" : "forward" , "indexBounds" : { "_id" : [ "[0.0, 8.0]" ] }, "keysExamined" : 3, "seeks" : 1, "dupsTested" : 0, "dupsDropped" : 0, "seenInvalidated" : 0 } } } } }, { "shardName" : "shard0000" , "executionSuccess" : true , "executionStages" : { "stage" : "LIMIT" , "nReturned" : 3, "executionTimeMillisEstimate" : 0, "works" : 4, "advanced" : 3, "needTime" : 0, "needYield" : 0, "saveState" : 0, "restoreState" : 0, "isEOF" : 1, "invalidates" : 0, "limitAmount" : 3, "inputStage" : { "stage" : "FETCH" , "nReturned" : 3, "executionTimeMillisEstimate" : 0, "works" : 3, "advanced" : 3, "needTime" : 0, "needYield" : 0, "saveState" : 0, "restoreState" : 0, "isEOF" : 0, "invalidates" : 0, "docsExamined" : 3, "alreadyHasObj" : 0, "inputStage" : { "stage" : "SHARDING_FILTER" , "nReturned" : 3, "executionTimeMillisEstimate" : 0, "works" : 3, "advanced" : 3, "needTime" : 0, "needYield" : 0, "saveState" : 0, "restoreState" : 0, "isEOF" : 0, "invalidates" : 0, "chunkSkips" : 0, "inputStage" : { "stage" : "IXSCAN" , "nReturned" : 3, "executionTimeMillisEstimate" : 0, "works" : 3, "advanced" : 3, "needTime" : 0, "needYield" : 0, "saveState" : 0, "restoreState" : 0, "isEOF" : 0, "invalidates" : 0, "keyPattern" : { "_id" : 1 }, "indexName" : "_id_" , "isMultiKey" : false , "multiKeyPaths" : { "_id" : [ ] }, "isUnique" : true , "isSparse" : false , "isPartial" : false , "indexVersion" : 2, "direction" : "forward" , "indexBounds" : { "_id" : [ "[0.0, 8.0]" ] }, "keysExamined" : 3, "seeks" : 1, "dupsTested" : 0, "dupsDropped" : 0, "seenInvalidated" : 0 } } } } } ] }, "allPlansExecution" : [ { "shardName" : "shard0001" , "allPlans" : [ ] }, { "shardName" : "shard0000" , "allPlans" : [ ] } ] }, "ok" : 1, "$clusterTime" : { "clusterTime" : Timestamp(1515170644, 1), "signature" : { "hash" : BinData(0, "AAAAAAAAAAAAAAAAAAAAAAAAAAA=" ), "keyId" : NumberLong(0) } }, "operationTime" : Timestamp(1515170644, 1) }