[SERVER-61244] Investigate performance of $group + $top compared to covered $sort + $group + $first plan against timeseries collection Created: 04/Nov/21 Updated: 16/Nov/21 Resolved: 16/Nov/21 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | None |
| Type: | Task | Priority: | Major - P3 |
| Reporter: | Mihai Andrei | Assignee: | Ruslan Abdulkhalikov (Inactive) |
| Resolution: | Done | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Sprint: | QE 2021-11-15, QE 2021-11-29 |
| Participants: |
| Description |
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This should also compare the $group + $top pipeline against the $lookup workaround that exists. |
| Comments |
| Comment by Ruslan Abdulkhalikov (Inactive) [ 10/Nov/21 ] |
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| Comment by Pawel Terlecki [ 09/Nov/21 ] |
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The new optimization is crushing it. Nice. 1. Is it a single machine test? 2. Were the measurements taken on cold or warm data caches? It seems to me that all the data should fit in memory in all these cases. If the caches were indeed warm, how could count take a second or $group/topn 14 seconds? |