[SERVER-83533] Improve efficiency of SBE when running projections with same prefix Created: 22/Nov/23 Updated: 24/Nov/23 Resolved: 24/Nov/23 |
|
| Status: | Closed |
| Project: | Core Server |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | None |
| Type: | Improvement | Priority: | Major - P3 |
| Reporter: | Carlos Alonso Pérez | Assignee: | Backlog - Query Execution |
| Resolution: | Duplicate | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Attachments: |
|
||||||||
| Issue Links: |
|
||||||||
| Assigned Teams: |
Query Execution
|
||||||||
| Participants: | |||||||||
| Description |
|
In SBE projections are isolated but there are cases where there are many projections sharing the same prefix e.g:
In the above example all the work to navigate up until c is repeated and thrown away on every projected field.
See the attached flame graph, query and explain plan for a real life example derived from HELP-47436 |