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Type:
Task
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Resolution: Fixed
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Priority:
Major - P3
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Affects Version/s: None
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Component/s: manual
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Labels:None
Description
Downstream Change Summary
The $currentDate update operator is being deprecated for MongoDB 4.4. As an alternative users can rewrite their updates using updates with aggregation pipelines and can use the $$NOW and $$CLUSTER_TIME aggregation system variables to access the current wall-clock and cluster time.
In the following example, a document is updated using pipeline updates and $$NOW:
> db.test.insert({_id: 1, value: null, lastUpdated: null})
WriteResult({ "nInserted" : 1 })
> db.test.find()
{ "_id" : 1, "value" : null, "lastUpdated" : null }
> db.test.update({_id: 1}, [{$set: {value: 1, lastUpdated: "$$NOW"}}])
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
> db.test.find()
{ "_id" : 1, "value" : 1, "lastUpdated" : ISODate("2019-10-01T13:27:55.583Z") }
Description of Linked Ticket
This can be better expressed using $$NOW and $$CLUSTER_TIME within a pipeline-style update and having two ways to do the same thing is confusing.
Scope of changes
Impact to Other Docs
MVP (Work and Date)
Resources (Scope or Design Docs, Invision, etc.)
- documents
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- Backlog
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