Details
Description
For a query like
{x: {$not: {$in: [["String"]]}} |
a collection scan will return the document
{x: "String"} |
because "String" != ["String"] and so "String" is not in the array [["String"]]. However, if you build an index on {x: 1} then the above document is not returned. Using explain, you can see the index bounds are:
{
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"x" : [
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"[MinKey, \"String\")",
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"(\"String\", [ \"String\" ])",
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"([ \"String\" ], MaxKey]"
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]
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}
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Compare this to what should be the equivalent query
{x: {$ne: ["String"]}} |
we then get the bounds:
{
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"x" : [
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"[MinKey, [ \"String\" ])",
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"([ \"String\" ], [ [ \"String\" ] ])",
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"([ [ \"String\" ] ], MaxKey]"
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]
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}
|
It looks like the index bounds building logic for an $in within a $not.
Attachments
Issue Links
- causes
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SERVER-40691 $nin:[[],...] queries are not indexed
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- Closed
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- related to
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SERVER-39764 Negation of $in with embedded array can incorrectly plan from the cache, triggering invariant
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- Closed
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