Revert "SERVER-45530 Implement $match and $project duplication and pushdown across $unionWith"

This reverts commit 942ec3300e82672536f34d8273314c5504ae91fb.

1 files changed, 2 insertions, 23 deletions

diff --git a/src/mongo/db/pipeline/document_source_union_with.h b/src/mongo/db/pipeline/document_source_union_with.h
index beb69c7e9e5..ba0327a4be2 100644
--- a/src/mongo/db/pipeline/document_source_union_with.h
+++ b/src/mongo/db/pipeline/document_source_union_with.h
@@ -80,15 +80,10 @@ public:
         std::vector<Value>& array,
         boost::optional<ExplainOptions::Verbosity> explain = boost::none) const final;
 
-    GetModPathsReturn getModifiedPaths() const final {
-        // Since we might have a document arrive from the foreign pipeline with the same path as a
-        // document in the main pipeline. Without introspecting the sub-pipeline, we must report
-        // that all paths have been modified.
-        return {GetModPathsReturn::Type::kAllPaths, {}, {}};
-    }
+    GetModPathsReturn getModifiedPaths() const final;
 
     StageConstraints constraints(Pipeline::SplitState) const final {
-        auto constraints = StageConstraints(
+        return StageConstraints(
             StreamType::kStreaming,
             PositionRequirement::kNone,
             HostTypeRequirement::kAnyShard,
@@ -99,13 +94,6 @@ public:
             // outside of the constraints as long as the involved namespaces are reported correctly.
             LookupRequirement::kAllowed,
             UnionRequirement::kAllowed);
-
-        // DocumentSourceUnionWith cannot directly swap with match but it contains custom logic in
-        // the doOptimizeAt() member function to allow itself to duplicate any match ahead in the
-        // current pipeline and place one copy inside its sub-pipeline and one copy behind in the
-        // current pipeline.
-        constraints.canSwapWithMatch = false;
-        return constraints;
     }
 
     DepsTracker::State getDependencies(DepsTracker* deps) const final;
@@ -123,15 +111,6 @@ public:
 
 protected:
     GetNextResult doGetNext() final;
-
-    Pipeline::SourceContainer::iterator doOptimizeAt(Pipeline::SourceContainer::iterator itr,
-                                                     Pipeline::SourceContainer* container) final;
-
-    boost::intrusive_ptr<DocumentSource> optimize() final {
-        _pipeline->optimizePipeline();
-        return this;
-    }
-
     void doDispose() final;
 
 private: