[SERVER-58548] Support accumulator initializer expression in HashAgg Created: 14/Jul/21 Updated: 06/Dec/22 Resolved: 11/Oct/21 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | Query Execution |
| Affects Version/s: | None |
| Fix Version/s: | None |
| Type: | Task | Priority: | Major - P3 |
| Reporter: | Eric Cox (Inactive) | Assignee: | Backlog - Query Execution |
| Resolution: | Won't Fix | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Assigned Teams: |
Query Execution
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| Participants: |
| Description |
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Each accumulator has an initializer expression that can be used to initialize an accumulator in certain scenarios. One example of this is when DSGroup creates a fresh group, and another is when DSGroup reads spilled accumulator states from disk and re-initializes groups. We need a mechanism to initialize agg expressions in sbe. This could be done by augmenting HashAgg to evaluate an initializer expression. We can think of other ways as well. |
| Comments |
| Comment by Ethan Zhang (Inactive) [ 11/Oct/21 ] |
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Spiling implementation will take care of this for us. |