| Steps To Reproduce: |
With the following indexes:
> db.accounts.getIndexes()
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[
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{
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"v" : 1,
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"key" : {
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"_id" : 1
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},
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"name" : "_id_",
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"ns" : "socialdb_prod.accounts"
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},
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{
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"v" : 1,
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"unique" : true,
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"key" : {
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"service" : 1,
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"uid" : 1
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},
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"name" : "service_1_uid_1",
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"background" : true,
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"dropDups" : true,
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"ns" : "socialdb_prod.accounts"
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}
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]
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Run a search:
db.accounts.find({"service": 0, "uid": "26119042"}).sort({_id: 1})
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Uses _id index instead of the obvious
{ service: 1, uid: 1 }
2014-11-13T19:29:57.910+0000 [conn1530188] query socialdb_prod.accounts query: { query: { service: 0.0, uid: "26119042" }, orderby: { _id: 1.0 } } planSummary: IXSCAN { _id: 1 } ntoreturn:0 ntoskip:0 nscanned:3575682 nscannedObjects:3575682 keyUpdates:0 numYields:4 locks(micros) r:8240040 nreturned:1 reslen:334 4285ms
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