diff --git a/velox/exec/HashBuild.cpp b/velox/exec/HashBuild.cpp
index 09058c2bdcba..e5f5ae639025 100644
--- a/velox/exec/HashBuild.cpp
+++ b/velox/exec/HashBuild.cpp
@@ -73,7 +73,7 @@ HashBuild::HashBuild(
 
   joinBridge_->addBuilder();
 
-  auto inputType = joinNode_->sources()[1]->outputType();
+  const auto& inputType = joinNode_->sources()[1]->outputType();
 
   const auto numKeys = joinNode_->rightKeys().size();
   keyChannels_.reserve(numKeys);
diff --git a/velox/exec/HashBuild.h b/velox/exec/HashBuild.h
index ac1606706ff5..f3534706c0f4 100644
--- a/velox/exec/HashBuild.h
+++ b/velox/exec/HashBuild.h
@@ -29,7 +29,7 @@ namespace facebook::velox::exec {
 // Builds a hash table for use in HashProbe. This is the final
 // Operator in a build side Driver. The build side pipeline has
 // multiple Drivers, each with its own HashBuild. The build finishes
-// when the last Driver of the build pipeline finishes. Hence finish()
+// when the last Driver of the build pipeline finishes. Hence finishHashBuild()
 // has a barrier where the last one to enter gathers the data
 // accumulated by the other Drivers and makes the join hash
 // table. This table is then passed to the probe side pipeline via