[DOCS-14488] Investigate changes in SERVER-56484: SBE explain execution stats include both "nReturned" and "advanced", which duplicate each other Created: 21/May/21  Updated: 13/Nov/23  Resolved: 06/Jan/22

Status: Closed
Project: Documentation
Component/s: manual, Server
Affects Version/s: None
Fix Version/s: 5.0.0-rc0, 5.1.0-rc0, Server_Docs_20231030, Server_Docs_20231106, Server_Docs_20231105, Server_Docs_20231113

Type: Task Priority: Major - P3
Reporter: Backlog - Core Eng Program Management Team Assignee: Jocelyn Mendez
Resolution: Fixed Votes: 0
Labels: None
Remaining Estimate: Not Specified
Time Spent: Not Specified
Original Estimate: Not Specified

Issue Links:
Backports
backported by DOCS-14493 [BACKPORT] [v5.0] SBE explain executi... Closed
Documented
documents SERVER-56484 SBE explain execution stats include b... Closed
Participants:
Days since reply: 2 years, 3 weeks ago
Epic Link: DOCSP-14300

 Description   

Description

Downstream Change Summary

The change modifies ouput of explain("executionStats").executionStats in SBE mode.

Description of Linked Ticket

When we display the full execution stats associated with an SBE plan in explain, each SBE stage reports both nReturned and advanced. For example:

			"stage" : "nlj",
			"planNodeId" : 1,
			"nReturned" : 3,
			"executionTimeMillisEstimate" : 0,
			"advances" : 3,
			"opens" : 1,
			"closes" : 1,
			"saveState" : 0,
			"restoreState" : 0,
			"isEOF" : 1,
			"innerOpens" : 1,
			"innerCloses" : 1,
			"outerProjects" : [
				NumberLong(4)
			],
			"outerCorrelated" : [
				NumberLong(7),
				NumberLong(8)
			],

This is a nested loop join stage. It has both nReturned and advanced which are both equal to 3. These two fields have the exact same meaning and report the exact same information. We should eliminate this redundancy. Since nReturned is a well-known field name from the format for explainVersion:"1", we should probably deleted advanced and keep reporting this statistic under the field name nReturned.

Scope of changes

Impact to Other Docs

MVP (Work and Date)

Resources (Scope or Design Docs, Invision, etc.)



 Comments   
Comment by Githook User [ 20/Jan/22 ]

Author:

{'name': 'jocelyn-mendez1', 'email': '91144778+jocelyn-mendez1@users.noreply.github.com', 'username': 'jocelyn-mendez1'}

Message: DOCS-14488 SBE mode no longer shows executionStage.advanced only executionStage.nReturned instead (#73)

Co-authored-by: Jocelyn Mendez <jocelyn.mendez@Jocelyns-MacBook-Pro.local>
Branch: v5.2
https://github.com/10gen/docs-mongodb-internal/commit/05ed06ffb4bbc2e9cc8f239b6b5870f852e42a4c

Comment by Githook User [ 10/Jan/22 ]

Author:

{'name': 'jocelyn-mendez1', 'email': '91144778+jocelyn-mendez1@users.noreply.github.com', 'username': 'jocelyn-mendez1'}

Message: DOCS-14488 SBE mode no longer shows executionStage.advanced only executionStage.nReturned instead (#73)

Co-authored-by: Jocelyn Mendez <jocelyn.mendez@Jocelyns-MacBook-Pro.local>
Branch: v5.3
https://github.com/mongodb/docs/commit/986bb1001f32d18ff476d036479835d020505143

Comment by Githook User [ 04/Jan/22 ]

Author:

{'name': 'jocelyn-mendez1', 'email': '91144778+jocelyn-mendez1@users.noreply.github.com', 'username': 'jocelyn-mendez1'}

Message: DOCS-14488 SBE mode no longer shows executionStage.advanced only executionStage.nReturned instead (#73)

Co-authored-by: Jocelyn Mendez <jocelyn.mendez@Jocelyns-MacBook-Pro.local>
Branch: master
https://github.com/mongodb/docs/commit/05ed06ffb4bbc2e9cc8f239b6b5870f852e42a4c

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