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Type:
Improvement
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Resolution: Done
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Priority:
Major - P3
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Affects Version/s: None
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Component/s: Aggregation Framework
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Fully Compatible
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Query 13 (04/22/16)
It's currently very expensive to perform a $match within the aggregation pipeline. This is mostly because the aggregation pipeline works with Documents, which are incompatible with the current MatchExpression::matchesBSON interface, so we have to construct an entirely new BSONObj to match on. There are two things we could do to make this more efficient:
- Instead of converting the entire Document to BSON, we could only convert the fields needed by the match. For example, if the match was {a: {$gte: 4}}, we would only need the field a from the document.
- We could extend the MatchExpression interface to support matching Documents. A Document is logically equivalent to a BSONObj, so it would just be a matter of adapting the matching to use a different API with the object.
- is duplicated by
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- Closed
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- is related to
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- Backlog
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- Closed
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- related to
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SERVER-27213 Two $match stages combine incorrectly, yielding incorrect results.
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- Closed
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SERVER-25911 Tune performance of $match stage
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- Closed
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