[SERVER-32943] Query during background index build can lead to suboptimal cached plan Created: 27/Jan/18 Updated: 29/Oct/23 Resolved: 09/May/18 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | Querying |
| Affects Version/s: | None |
| Fix Version/s: | 3.6.9, 4.0.0-rc0 |
| Type: | Bug | Priority: | Major - P3 |
| Reporter: | Chris Harris | Assignee: | James Wahlin |
| Resolution: | Fixed | Votes: | 0 |
| Labels: | None | ||
| 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 | ||||||||||||||||||||
| Backport Requested: |
v3.6, v3.4
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| Sprint: | Query 2018-05-07, Query 2018-05-21 | ||||||||||||||||||||
| Participants: | |||||||||||||||||||||
| Case: | (copied to CRM) | ||||||||||||||||||||
| Description |
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Building an index flushes the plan cache. If a query which could leverage the new index executes while the background build is still in progress, the query will be planned without the ability to consider the new index as a candidate. This plan can then get cached and there will be no further flushing done as a result of the build process. Further, the index in the cached plan may not be as selective as the newly created one, therefore it may be hard to evict the old plan without manual intervention. |
| Comments |
| Comment by Githook User [ 20/Sep/18 ] |
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Author: {'name': 'James Wahlin', 'email': 'james@mongodb.com', 'username': 'jameswahlin'}Message: (cherry picked from commit 2f20acfd0d462e7f6c1c1c59bd562c883f1db55d) |
| Comment by Githook User [ 09/May/18 ] |
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Author: {'email': 'james@mongodb.com', 'name': 'James Wahlin', 'username': 'jameswahlin'}Message: |