[SERVER-41279] Eliminate failed plans from consideration during query planning Created: 22/May/19 Updated: 29/Oct/23 Resolved: 19/Jul/19 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | Index Maintenance, Querying |
| Affects Version/s: | None |
| Fix Version/s: | 4.3.1 |
| Type: | Bug | Priority: | Major - P3 |
| Reporter: | Chris Harris | Assignee: | Sam Mercier |
| Resolution: | Fixed | Votes: | 0 |
| Labels: | query-44-grooming, storch | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Issue Links: |
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| Backwards Compatibility: | Fully Compatible | ||||
| Operating System: | ALL | ||||
| Sprint: | Query 2019-06-17, Query 2019-07-01, Query 2019-07-15, Query 2019-07-29 | ||||
| Participants: | |||||
| Linked BF Score: | 0 | ||||
| Description |
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Candidate plans can fail during the trial phase of the query planning process. A typical example would be when plans with blocking sorts exceed their configured memory threshold. Once failed, such plans should not be eligible for selection as the winning plan. As part of addressing this ticket, we should consider whether to remove the concept of a backup plan entirely from the code base. Backup plans were removed from the plan cache in 3.0 via There is at least one edge case for that situation which should be accounted for. If the blocking sort plan can provide a covered plan thus offsetting the noSortBonus tie breaker with the noFetchBonus:
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| Comments |
| Comment by Githook User [ 11/Jul/19 ] |
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Author: {'name': 'samontea', 'email': 'merciers.merciers@gmail.com', 'username': 'samontea'}Message: |
| Comment by Githook User [ 10/Jul/19 ] |
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Author: {'name': 'Xiangyu Yao', 'email': 'xiangyu.yao@mongodb.com', 'username': 'xy24'}Message: Revert " This reverts commit 6bba6446e632b557ccc03834d4d48e90336679fc. |
| Comment by Githook User [ 10/Jul/19 ] |
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Author: {'name': 'samontea', 'username': 'samontea', 'email': 'merciers.merciers@gmail.com'}Message: |
| Comment by Sam Mercier [ 31/May/19 ] |
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christopher.harris If it's okay with you, I'm going to move removing backup plans entirely from the code base from this ticket. It feels like substantially different work from what's described in the rest of the ticket. |