[SERVER-59830] Share BSONColumn across BucketUnpackers in TrialStage Created: 08/Sep/21 Updated: 06/Dec/22 Resolved: 08/Sep/21 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | None |
| 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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https://github.com/10gen/mongo/pull/426#discussion_r697471248 While the work done in each TrialStage might be a little different, if they share the same `BSONColumn` then any bucket that has been previously unpacked and hence uncompressed will be cached and should give a perf gain. We should see how we can best share the `BSONColumn` across multiple BucketUnapckers. |
| Comments |
| Comment by Eric Cox (Inactive) [ 08/Sep/21 ] |
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Since the BucketUnpackers in each branch will see different buckets due to the randomness in SampleFromTimeseries and the backup branch will be scanning the buckets, it turns out that this won't benefit from sharing a BSONColumn. The only time we should consider sharing BSONColumns is if we see the same buckets in each BucketUnpacker in lock-step. This isn't the case here so I'm closing this ticket. cc: henrik.edin |