SERVER-69103 Always use the classic engine on the inner side of DocumentSourceLookup or $graphLookup

3 files changed, 5 insertions, 2 deletions

diff --git a/src/mongo/db/pipeline/document_source_graph_lookup.cpp b/src/mongo/db/pipeline/document_source_graph_lookup.cpp
index a02c02e10fd..666d8952284 100644
--- a/src/mongo/db/pipeline/document_source_graph_lookup.cpp
+++ b/src/mongo/db/pipeline/document_source_graph_lookup.cpp
@@ -656,6 +656,7 @@ DocumentSourceGraphLookUp::DocumentSourceGraphLookUp(
       _variablesParseState(expCtx->variablesParseState.copyWith(_variables.useIdGenerator())) {
     const auto& resolvedNamespace = pExpCtx->getResolvedNamespace(_from);
     _fromExpCtx = pExpCtx->copyForSubPipeline(resolvedNamespace.ns, resolvedNamespace.uuid);
+    _fromExpCtx->inLookup = true;
 
     // We append an additional BSONObj to '_fromPipeline' as a placeholder for the $match stage
     // we'll eventually construct from the input document.
diff --git a/src/mongo/db/pipeline/expression_context.h b/src/mongo/db/pipeline/expression_context.h
index df650699f06..0d2d87fd361 100644
--- a/src/mongo/db/pipeline/expression_context.h
+++ b/src/mongo/db/pipeline/expression_context.h
@@ -436,7 +436,7 @@ public:
     // Tracks the depth of nested aggregation sub-pipelines. Used to enforce depth limits.
     long long subPipelineDepth = 0;
 
-    // True if this 'ExpressionContext' object is for the inner side of a $lookup.
+    // True if this 'ExpressionContext' object is for the inner side of a $lookup or $graphLookup.
     bool inLookup = false;
 
     // If set, this will disallow use of features introduced in versions above the provided version.
diff --git a/src/mongo/db/query/sbe_utils.cpp b/src/mongo/db/query/sbe_utils.cpp
index 58649249841..02deffee4ae 100644
--- a/src/mongo/db/query/sbe_utils.cpp
+++ b/src/mongo/db/query/sbe_utils.cpp
@@ -64,9 +64,11 @@ bool isQuerySbeCompatible(const CollectionPtr* collection,
 
     const bool doesNotHaveElemMatchProject = !cq->getProj() || !cq->getProj()->containsElemMatch();
 
+    const bool isNotInnerSideOfLookup = !(expCtx && expCtx->inLookup);
+
     return allExpressionsSupported && isNotCount && doesNotContainMetadataRequirements &&
         isQueryNotAgainstTimeseriesCollection && isQueryNotAgainstClusteredCollection &&
         doesNotSortOnMetaOrPathWithNumericComponents && isNotOplog && doesNotRequireMatchDetails &&
-        doesNotHaveElemMatchProject && isNotChangeCollection;
+        doesNotHaveElemMatchProject && isNotChangeCollection && isNotInnerSideOfLookup;
 }
 }  // namespace mongo::sbe