[SERVER-79764] Ensure that streaming group over TS keeps running fully classic Created: 04/Aug/23 Updated: 26/Sep/23 Resolved: 26/Sep/23 |
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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: | Irina Yatsenko (Inactive) | Assignee: | Backlog - Query Integration |
| Resolution: | Duplicate | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Issue Links: |
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| Assigned Teams: |
Query Integration
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| Description |
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See PM-3050 – streaming group is one of the optimizations, added in that project. It replaces $group with $_internalStreamingGroup if the input into the group is sorted on time and the group’s key includes a monotonic derivative of time. $_internalStreamingGroup isn’t supported in SBE and while the query could benefit from lowering the prefix up to it, we’d rather not risk perf regressions and block it from running in the hybrid mode until $_internalStreamingGroup is implemented in SBE. |
| Comments |
| Comment by Irina Yatsenko (Inactive) [ 26/Sep/23 ] |
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The streaming group optimization requires sorting on time similar to the bounded sort optimization so we'll be blocking both by not allowing to lower to SBE pipelines with $sort on the timeField. |