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Type:
Improvement
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Resolution: Won't Fix
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Priority:
Major - P3
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None
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Affects Version/s: 2.6.4, 2.7.5
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Component/s: Querying
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None
In MongoDB 2.4.11, the bounds specified by $min/$max are included in the top-level indexBounds field of explain (as "start" and "end" sub-documents). However, when using $min/$max with MongoDB 2.6, these fields are not present. The index bounds are visible only in the "boundsVerbose" field of the IXSCAN stage ("indexBounds" in 2.7.5/master). Can the index-key-range-based bounds that are set by $min/$max be shown in the top-level indexBounds field, as they were in 2.4?
For example, given the index { b: 1, e: 1, f: 1, _id: 1 }, these queries behave as below in MongoDB 2.4.11:
> db.test.find({a: "foo", b: { $gte: 1, $lte: 3 }, c: 1, d: 2014, e: true, f: 1, _id: { $ne: 105 }}).min({b:1,e:true,f:1,_id:0}).max({b:3,e:true,f:1,_id:100000}).explain()
{
"cursor" : "BtreeCursor b_1_e_1_f_1__id_1",
"isMultiKey" : false,
"n" : 2,
"nscannedObjects" : 945,
"nscanned" : 945,
"nscannedObjectsAllPlans" : 945,
"nscannedAllPlans" : 945,
"scanAndOrder" : false,
"indexOnly" : false,
"nYields" : 0,
"nChunkSkips" : 0,
"millis" : 3,
"indexBounds" : {
"start" : {
"b" : 1,
"e" : true,
"f" : 1,
"_id" : 0
},
"end" : {
"b" : 3,
"e" : true,
"f" : 1,
"_id" : 100000
}
},
"server" : "genique:14804",
"millis" : 3
}
Whereas in MongoDB 2.6.4:
> db.test.find({a: "foo", b: { $gte: 1, $lte: 3 }, c: 1, d: 2014, e: true, f: 1, _id: { $ne: 105 }}).min({b:1,e:true,f:1,_id:0}).max({b:3,e:true,f:1,_id:100000}).explain()
{
"cursor" : "BtreeCursor b_1_e_1_f_1__id_1",
"isMultiKey" : false,
"n" : 2,
"nscannedObjects" : 945,
"nscanned" : 946,
"nscannedObjectsAllPlans" : 945,
"nscannedAllPlans" : 946,
"scanAndOrder" : false,
"indexOnly" : false,
"nYields" : 7,
"nChunkSkips" : 0,
"millis" : 6,
"indexBounds" : {
},
"server" : "genique:24802",
"filterSet" : false,
"stats" : {
"type" : "KEEP_MUTATIONS",
"works" : 947,
"yields" : 7,
"unyields" : 7,
"invalidates" : 0,
"advanced" : 2,
"needTime" : 944,
"needFetch" : 0,
"isEOF" : 1,
"children" : [
{
"type" : "FETCH",
"works" : 947,
"yields" : 7,
"unyields" : 7,
"invalidates" : 0,
"advanced" : 2,
"needTime" : 944,
"needFetch" : 0,
"isEOF" : 1,
"alreadyHasObj" : 0,
"forcedFetches" : 0,
"matchTested" : 2,
"children" : [
{
"type" : "IXSCAN",
"works" : 946,
"yields" : 7,
"unyields" : 7,
"invalidates" : 0,
"advanced" : 945,
"needTime" : 1,
"needFetch" : 0,
"isEOF" : 1,
"keyPattern" : "{ b: 1.0, e: 1.0, f: 1.0, _id: 1.0 }",
"isMultiKey" : 0,
"boundsVerbose" : "[{ : 1.0, : true, : 1.0, : 0.0 }, { : 3.0, : true, : 1.0, : 100000.0 })",
"yieldMovedCursor" : 0,
"dupsTested" : 0,
"dupsDropped" : 0,
"seenInvalidated" : 0,
"matchTested" : 0,
"keysExamined" : 946,
"children" : [ ]
}
]
}
]
}
}
and 2.7.5:
> db.test.find({a: "foo", b: { $gte: 1, $lte: 3 }, c: 1, d: 2014, e: true, f: 1, _id: { $ne: 105 }}).min({b:1,e:true,f:1,_id:0}).max({b:3,e:true,f:1,_id:100000}).explain()
{
"cursor" : "BtreeCursor b_1_e_1_f_1__id_1",
"isMultiKey" : false,
"n" : 2,
"nscannedObjects" : 945,
"nscanned" : 946,
"nscannedObjectsAllPlans" : 945,
"nscannedAllPlans" : 946,
"scanAndOrder" : false,
"indexOnly" : false,
"nYields" : 0,
"nChunkSkips" : 0,
"millis" : 2,
"indexBounds" : {
},
"server" : "genique:24802",
"stats" : {
"stage" : "KEEP_MUTATIONS",
"nReturned" : 2,
"executionTimeMillis" : 2,
"works" : 947,
"advanced" : 2,
"needTime" : 944,
"isEOF" : 1,
"invalidates" : 0,
"inputStage" : {
"stage" : "FETCH",
"filter" : {
"$and" : [
{
"$not" : {
"_id" : {
"$eq" : 105
}
}
},
{
"b" : {
"$lte" : 3
}
},
{
"a" : {
"$eq" : "foo"
}
},
{
"c" : {
"$eq" : 1
}
},
{
"d" : {
"$eq" : 2014
}
},
{
"e" : {
"$eq" : true
}
},
{
"f" : {
"$eq" : 1
}
},
{
"b" : {
"$gte" : 1
}
}
]
},
"nReturned" : 2,
"executionTimeMillis" : 2,
"works" : 947,
"advanced" : 2,
"needTime" : 944,
"isEOF" : 1,
"invalidates" : 0,
"docsExamined" : 945,
"alreadyHasObj" : 0,
"inputStage" : {
"stage" : "IXSCAN",
"nReturned" : 945,
"executionTimeMillis" : 1,
"works" : 946,
"advanced" : 945,
"needTime" : 1,
"isEOF" : 1,
"invalidates" : 0,
"keysExamined" : 946,
"keyPattern" : {
"b" : 1,
"e" : 1,
"f" : 1,
"_id" : 1
},
"isMultiKey" : false,
"indexBounds" : "[{ : 1.0, : true, : 1.0, : 0.0 }, { : 3.0, : true, : 1.0, : 100000.0 })",
"dupsTested" : 0,
"dupsDropped" : 0,
"seenInvalidated" : 0,
"matchTested" : 0
}
}
}
}
- related to
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- Closed
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