diff --git a/src/Interpreters/OptimizeShardingKeyRewriteInVisitor.cpp b/src/Interpreters/OptimizeShardingKeyRewriteInVisitor.cpp
index 4d1c0526910..a031b8dc962 100644
--- a/src/Interpreters/OptimizeShardingKeyRewriteInVisitor.cpp
+++ b/src/Interpreters/OptimizeShardingKeyRewriteInVisitor.cpp
@@ -13,7 +13,7 @@ using namespace DB;
 
 Field executeFunctionOnField(
     const Field & field, const std::string & name,
-    const ExpressionActionsPtr & expr,
+    const ExpressionActionsPtr & sharding_expr,
     const std::string & sharding_key_column_name)
 {
     DataTypePtr type = applyVisitor(FieldToDataType{}, field);
@@ -25,17 +25,23 @@ Field executeFunctionOnField(
 
     Block block{column};
     size_t num_rows = 1;
-    expr->execute(block, num_rows);
+    sharding_expr->execute(block, num_rows);
 
     ColumnWithTypeAndName & ret = block.getByName(sharding_key_column_name);
     return (*ret.column)[0];
 }
 
-/// Return true if shard may contain such value (or it is unknown), otherwise false.
+/// @param sharding_column_value - one of values from IN
+/// @param sharding_column_name - name of that column
+/// @param sharding_expr - expression of sharding_key for the Distributed() table
+/// @param sharding_key_column_name - name of the column for sharding_expr
+/// @param shard_info - info for the current shard (to compare shard_num with calculated)
+/// @param slots - weight -> shard mapping
+/// @return true if shard may contain such value (or it is unknown), otherwise false.
 bool shardContains(
     const Field & sharding_column_value,
     const std::string & sharding_column_name,
-    const ExpressionActionsPtr & expr,
+    const ExpressionActionsPtr & sharding_expr,
     const std::string & sharding_key_column_name,
     const Cluster::ShardInfo & shard_info,
     const Cluster::SlotToShard & slots)
@@ -45,7 +51,7 @@ bool shardContains(
     if (sharding_column_value.isNull())
         return false;
 
-    Field sharding_value = executeFunctionOnField(sharding_column_value, sharding_column_name, expr, sharding_key_column_name);
+    Field sharding_value = executeFunctionOnField(sharding_column_value, sharding_column_name, sharding_expr, sharding_key_column_name);
     UInt64 value = sharding_value.get<UInt64>();
     const auto shard_num = slots[value % slots.size()] + 1;
     return shard_info.shard_num == shard_num;
@@ -78,10 +84,10 @@ void OptimizeShardingKeyRewriteInMatcher::visit(ASTFunction & function, Data & d
     if (!identifier)
         return;
 
-    const auto & expr = data.sharding_key_expr;
+    const auto & sharding_expr = data.sharding_key_expr;
     const auto & sharding_key_column_name = data.sharding_key_column_name;
 
-    if (!expr->getRequiredColumnsWithTypes().contains(identifier->name()))
+    if (!sharding_expr->getRequiredColumnsWithTypes().contains(identifier->name()))
         return;
 
     /// NOTE: that we should not take care about empty tuple,
@@ -93,7 +99,7 @@ void OptimizeShardingKeyRewriteInMatcher::visit(ASTFunction & function, Data & d
         std::erase_if(tuple_elements->children, [&](auto & child)
         {
             auto * literal = child->template as<ASTLiteral>();
-            return literal && !shardContains(literal->value, identifier->name(), expr, sharding_key_column_name, data.shard_info, data.slots);
+            return literal && !shardContains(literal->value, identifier->name(), sharding_expr, sharding_key_column_name, data.shard_info, data.slots);
         });
     }
     else if (auto * tuple_literal = right->as<ASTLiteral>();
@@ -102,7 +108,7 @@ void OptimizeShardingKeyRewriteInMatcher::visit(ASTFunction & function, Data & d
         auto & tuple = tuple_literal->value.get<Tuple &>();
         std::erase_if(tuple, [&](auto & child)
         {
-            return !shardContains(child, identifier->name(), expr, sharding_key_column_name, data.shard_info, data.slots);
+            return !shardContains(child, identifier->name(), sharding_expr, sharding_key_column_name, data.shard_info, data.slots);
         });
     }
 }