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| author | David Storch <david.storch@10gen.com> | 2018-09-26 13:51:06 -0400 |
|---|---|---|
| committer | David Storch <david.storch@10gen.com> | 2018-10-03 16:03:23 -0400 |
| commit | 5b30d4be9e43ef9d12b409a7249649806374b2e9 (patch) | |
| tree | 261957b15ab68c16b0d173a01902caaf0c524a0b /src/mongo/db/query/planner_ixselect.cpp | |
| parent | 231ec00544f7415bfcdcc51fabc55df6c7e6cb31 (diff) | |
| download | mongo-5b30d4be9e43ef9d12b409a7249649806374b2e9.tar.gz | |
SERVER-36896 Allow wildcard indices to support equality to empty object predicates.
Diffstat (limited to 'src/mongo/db/query/planner_ixselect.cpp')
| -rw-r--r-- | src/mongo/db/query/planner_ixselect.cpp | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/src/mongo/db/query/planner_ixselect.cpp b/src/mongo/db/query/planner_ixselect.cpp index 8a7f005d9c1..08a78e95491 100644 --- a/src/mongo/db/query/planner_ixselect.cpp +++ b/src/mongo/db/query/planner_ixselect.cpp @@ -130,7 +130,14 @@ void expandIndex(const IndexEntry& wildcardIndex, bool canUseWildcardIndex(BSONElement elt, MatchExpression::MatchType matchType) { if (elt.type() == BSONType::Object) { - return false; + // $** indices break nested objects into separate keys, which means we can't naturally + // support comparison-to-object predicates. However, there is an exception: empty objects + // are indexed like regular leaf values. This means that equality-to-empty-object can be + // supported. + // + // Due to type bracketing, $lte:{} and $eq:{} are semantically equivalent. + return elt.embeddedObject().isEmpty() && + (matchType == MatchExpression::EQ || matchType == MatchExpression::LTE); } if (elt.type() == BSONType::Array) { |