[SERVER-74868] [CQF] Refine Costing for Spool-based RIN Created: 14/Mar/23 Updated: 20/Apr/23 |
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| Status: | Open |
| Project: | Core Server |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | None |
| Type: | Improvement | Priority: | Major - P3 |
| Reporter: | Svilen Mihaylov (Inactive) | Assignee: | Backlog - Query Optimization |
| Resolution: | Unresolved | 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 Optimization
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| Participants: | |||||||||
| Description |
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Currently we assign the group-level CE to all operators involved in the spool based RIN. Instead, for the inner distinct scans we should attempt to estimate the number of distinct values in order to allow costing to compute a more realistic plan cost. This can be some global heuristic (say 10% of the values are unique) or some simple function initially. |