[DOCS-7237] Ambiguity about Where the Merge Sort Occurs in a Sharded Cluster Created: 23/Feb/16 Updated: 14/Apr/22 Resolved: 05/Feb/18 |
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| Status: | Closed |
| Project: | Documentation |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | None |
| Type: | Bug | Priority: | Major - P3 |
| Reporter: | William Cross | Assignee: | Susan Kerschbaumer (Inactive) |
| Resolution: | Done | Votes: | 0 |
| Labels: | None | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Issue Links: |
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| Days since reply: | 1 year, 42 weeks, 6 days ago | ||||||||||||||||||||||||||||
| Story Points: | 0.5 | ||||||||||||||||||||||||||||
| Description |
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The documentation states, in different places, that a merge sort occurs on the mongos, or on the Primary database of the collection. The documentation may need to be reconciled, or, if I'm misunderstanding what's being communicated, clarified. I believe that the mongos is the only shard that merge-sorts the results of a .find() query. Statements in favor of each:
I also note that the explanation references the $orderby option, which, according to the documentation, is deprecated as of 3.2. |
| Comments |
| Comment by Jess Mokrzecki [ 14/Apr/22 ] |
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Fix Version updated for upstream SERVER-17737: |
| Comment by Ravind Kumar (Inactive) [ 09/Oct/18 ] |
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asya is |
| Comment by Githook User [ 06/Feb/18 ] |
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Author: {'email': 'sue.kerschbaumer@10gen.com', 'name': 'skerschb', 'username': 'skerschb'}Message: |
| Comment by David Storch [ 11/Jan/18 ] |
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bernard.gorman completed a bunch of the work related to this in 3.6 and could be a good reviewer for proposed documentation changes. |
| Comment by Asya Kamsky [ 10/Jan/18 ] |
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This has changed in 3.6 for aggregation and that doesn't seem to be mentioned in the docs. |
| Comment by David Storch [ 07/Jul/16 ] |
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In 3.2.x versions:
In older versions (I think 2.6.x?) the mongos can perform merge operations, but only for aggregation operations. For find operations, mongos is responsible for doing the sorted merge in all versions of MongoDB. Since both of these links are documenting find (and not aggregation), the former link appears to be inaccurate whereas the latter link is correct. |
| Comment by Ravind Kumar (Inactive) [ 07/Jul/16 ] |
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david.storch, renctan, could either of you shed some light into which behavior is correct? or are both possible depending on the situation? |