Do not use the TS_MODIFY plan for an empty delete filter for multi delete

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    • Type: Task
    • Resolution: Fixed
    • Priority: Major - P3
    • 7.0.0-rc0
    • Affects Version/s: None
    • Component/s: None
    • None
    • Fully Compatible
    • Execution Team 2023-04-17
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      We use a TS_MODIFY plan for an empty filter, which means “delete all”, when a timeseries collection does not define a meta field.

      > db.createCollection("ts", {timeseries: {timeField: "t"}});
{ "ok" : 1 }
> db.ts.insert({t: new ISODate(), f: 1});
WriteResult({ "nInserted" : 1 })
> db.runCommand({explain: {delete: "ts", deletes: [{q: {}, limit: 0}]}, verbosity: "queryPlanner"});
		"winningPlan" : {
			"stage" : "TS_MODIFY",
			"opType" : "deleteMany",
			"bucketFilter" : {


			},
			"residualFilter" : {


			},
			"inputStage" : {
				"stage" : "COLLSCAN",
				"direction" : "forward"
			}
		},

      This would be better to not be a TS_MODIFY plan which will unpack every bucket. When there’s a meta field defined, we use BATCHED_DELETE.

            Assignee:
            Yoon Soo Kim (Inactive)
            Reporter:
            Yoon Soo Kim (Inactive)
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              Created:
              Updated:
              Resolved: