Tailable cursors do not honor $maxScan values

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    • Type: Bug
    • Resolution: Done
    • Priority: Major - P3
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    • Affects Version/s: 2.6.0, 2.6.1-rc0
    • Component/s: Querying
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    • ALL
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      db.createCollection("tailable", {size: 1000000, capped: true});

for (var i = 0; i < 10000; i++) {
    db.tailable.insert({i: i});
}

db.tailable.find().addOption(DBQuery.Option.tailable)._addSpecial("$maxScan", 100).explain();
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      db.createCollection("tailable", {size: 1000000, capped: true}); for (var i = 0; i < 10000; i++) { db.tailable.insert({i: i}); } db.tailable.find().addOption(DBQuery.Option.tailable)._addSpecial("$maxScan", 100).explain();
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      In 2.4.10, tailable cursors seem to honor $maxScan values:

      > db.tailable.find().addOption(DBQuery.Option.tailable)._addSpecial("$maxScan", 100).explain();
{
	"cursor" : "ForwardCappedCursor",
	"isMultiKey" : false,
	"n" : 100,
	"nscannedObjects" : 100,
	"nscanned" : 101,
	"nscannedObjectsAllPlans" : 100,
	"nscannedAllPlans" : 101,
...

      In 2.6 and 2.6.1-rc0, they do not:

      > db.tailable.find().addOption(DBQuery.Option.tailable)._addSpecial("$maxScan", 100).explain();
{
	"cursor" : "BasicCursor",
	"isMultiKey" : false,
	"n" : 10000,
	"nscannedObjects" : 10000,
	"nscanned" : 10000,
	"nscannedObjectsAllPlans" : 10000,
	"nscannedAllPlans" : 10000,
...

            Assignee:
            Unassigned
            Reporter:
            Kamran K. (Inactive)
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              Created:
              Updated:
              Resolved: