Details
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Bug
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Status: Closed
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Major - P3
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Resolution: Duplicate
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None
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None
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None
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ALL
Description
I have a collection with 2m records. unique index on _id and foo columns
db.col.aggregate([ { "$match" : { "foo" : "abcd" } }, { "$sort" : { "_id" : 1 } } ]) |
takes about 5 seconds to return;
db.col.aggregate([ { "$match" : { "foo" : "abcd" } } ]) |
returns instantly. An explain shows that the first one chooses to use the _id index for some reason therefore causing a whole table scan. I seem to recall this also being an issue back in mongo 2.4 but is still there in mongo 3
Attachments
Issue Links
- duplicates
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SERVER-7568 Aggregation framework favors non-blocking sorts
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- Closed
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- is related to
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SERVER-21502 $group using index
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- Closed
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