[SERVER-2538] MR: shouldn't create _id index in temp collection for merge or reduce output styles Created: 11/Feb/11 Updated: 06/Dec/22 Resolved: 09/Mar/20 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | Performance |
| Affects Version/s: | None |
| Fix Version/s: | None |
| Type: | Bug | Priority: | Major - P3 |
| Reporter: | Mathias Stearn | Assignee: | Backlog - Query Team (Inactive) |
| Resolution: | Done | Votes: | 1 |
| Labels: | query-44-grooming | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Issue Links: |
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| Assigned Teams: |
Query
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| Operating System: | ALL | ||||
| Participants: | |||||
| Comments |
| Comment by Charlie Swanson [ 09/Mar/20 ] |
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In a recent project we reimplemented mapReduce on top of the aggregation framework. In particular, these output modes now use $merge, which doesn't involve any temporary collections. |