diff --git a/dbms/include/DB/Interpreters/ExpressionAnalyzer.h b/dbms/include/DB/Interpreters/ExpressionAnalyzer.h
index d7111b1345f..d7a1350b4f5 100644
--- a/dbms/include/DB/Interpreters/ExpressionAnalyzer.h
+++ b/dbms/include/DB/Interpreters/ExpressionAnalyzer.h
@@ -182,6 +182,9 @@ private:
 	/// Например, для ARRAY JOIN [1,2] AS b сюда попадет "b" -> "array(1,2)".
 	NameToNameMap array_join_alias_to_name;
 
+	/// Обратное отображение для array_join_alias_to_name.
+	NameToNameMap array_join_name_to_alias;
+
 	/// Нужно ли подготавливать к выполнению глобальные подзапросы при анализировании запроса.
 	bool do_global;
 
diff --git a/dbms/src/Interpreters/ExpressionActions.cpp b/dbms/src/Interpreters/ExpressionActions.cpp
index 86f2647a01f..3d59cca3a2e 100644
--- a/dbms/src/Interpreters/ExpressionActions.cpp
+++ b/dbms/src/Interpreters/ExpressionActions.cpp
@@ -148,9 +148,9 @@ void ExpressionAction::prepare(Block & sample_block)
 
 		case ARRAY_JOIN:
 		{
-			for (NameSet::iterator it = array_joined_columns.begin(); it != array_joined_columns.end(); ++it)
+			for (const auto & name : array_joined_columns)
 			{
-				ColumnWithTypeAndName & current = sample_block.getByName(*it);
+				ColumnWithTypeAndName & current = sample_block.getByName(name);
 				const DataTypeArray * array_type = typeid_cast<const DataTypeArray *>(&*current.type);
 				if (!array_type)
 					throw Exception("ARRAY JOIN requires array argument", ErrorCodes::TYPE_MISMATCH);
@@ -214,6 +214,7 @@ void ExpressionAction::prepare(Block & sample_block)
 	}
 }
 
+
 void ExpressionAction::execute(Block & block) const
 {
 //	std::cerr << "executing: " << toString() << std::endl;
@@ -261,9 +262,11 @@ void ExpressionAction::execute(Block & block) const
 		{
 			if (array_joined_columns.empty())
 				throw Exception("No arrays to join", ErrorCodes::LOGICAL_ERROR);
+
 			ColumnPtr any_array_ptr = block.getByName(*array_joined_columns.begin()).column;
 			if (any_array_ptr->isConst())
 				any_array_ptr = dynamic_cast<const IColumnConst &>(*any_array_ptr).convertToFullColumn();
+
 			const ColumnArray * any_array = typeid_cast<const ColumnArray *>(&*any_array_ptr);
 			if (!any_array)
 				throw Exception("ARRAY JOIN of not array: " + *array_joined_columns.begin(), ErrorCodes::TYPE_MISMATCH);
diff --git a/dbms/src/Interpreters/ExpressionAnalyzer.cpp b/dbms/src/Interpreters/ExpressionAnalyzer.cpp
index 3c347d62a28..71b4fe794b5 100644
--- a/dbms/src/Interpreters/ExpressionAnalyzer.cpp
+++ b/dbms/src/Interpreters/ExpressionAnalyzer.cpp
@@ -1407,12 +1407,15 @@ void ExpressionAnalyzer::getArrayJoinedColumns()
 		{
 			const String nested_table_name = ast->getColumnName();
 			const String nested_table_alias = ast->getAliasOrColumnName();
+
 			if (nested_table_alias == nested_table_name && !typeid_cast<const ASTIdentifier *>(&*ast))
 				throw Exception("No alias for non-trivial value in ARRAY JOIN: " + nested_table_name, ErrorCodes::ALIAS_REQUIRED);
 
 			if (array_join_alias_to_name.count(nested_table_alias) || aliases.count(nested_table_alias))
 				throw Exception("Duplicate alias " + nested_table_alias, ErrorCodes::MULTIPLE_EXPRESSIONS_FOR_ALIAS);
+
 			array_join_alias_to_name[nested_table_alias] = nested_table_name;
+			array_join_name_to_alias[nested_table_name] = nested_table_alias;
 		}
 
 		ASTs & query_asts = select_query->children;
@@ -1455,6 +1458,7 @@ void ExpressionAnalyzer::getArrayJoinedColumns()
 }
 
 
+/// Заполняет array_join_result_to_source: по каким столбцам-массивам размножить, и как их после этого назвать.
 void ExpressionAnalyzer::getArrayJoinedColumnsImpl(ASTPtr ast)
 {
 	if (ASTIdentifier * node = typeid_cast<ASTIdentifier *>(&*ast))
@@ -1462,14 +1466,29 @@ void ExpressionAnalyzer::getArrayJoinedColumnsImpl(ASTPtr ast)
 		if (node->kind == ASTIdentifier::Column)
 		{
 			String table_name = DataTypeNested::extractNestedTableName(node->name);
+
 			if (array_join_alias_to_name.count(node->name))
-				array_join_result_to_source[node->name] = array_join_alias_to_name[node->name];
+			{
+				/// Был написан ARRAY JOIN со столбцом-массивом. Пример: SELECT K1 FROM ... ARRAY JOIN ParsedParams.Key1 AS K1
+				array_join_result_to_source[node->name] = array_join_alias_to_name[node->name];	/// K1 -> ParsedParams.Key1
+			}
 			else if (array_join_alias_to_name.count(table_name))
 			{
-				String nested_column = DataTypeNested::extractNestedColumnName(node->name);
-				array_join_result_to_source[node->name]
+				/// Был написан ARRAY JOIN с вложенной таблицей. Пример: SELECT PP.Key1 FROM ... ARRAY JOIN ParsedParams AS PP
+				String nested_column = DataTypeNested::extractNestedColumnName(node->name);	/// Key1
+				array_join_result_to_source[node->name]	/// PP.Key1 -> ParsedParams.Key1
 					= DataTypeNested::concatenateNestedName(array_join_alias_to_name[table_name], nested_column);
 			}
+			else if (array_join_name_to_alias.count(table_name))
+			{
+				/** Пример: SELECT ParsedParams.Key1 FROM ... ARRAY JOIN ParsedParams AS PP.
+				  * То есть, в запросе используется исходный массив, размноженный по самому себе.
+				  */
+
+				String nested_column = DataTypeNested::extractNestedColumnName(node->name);	/// Key1
+				array_join_result_to_source[	/// PP.Key1 -> ParsedParams.Key1
+					DataTypeNested::concatenateNestedName(array_join_name_to_alias[table_name], nested_column)] = node->name;
+			}
 		}
 	}
 	else
@@ -1511,10 +1530,12 @@ void ExpressionAnalyzer::getActionsImpl(ASTPtr ast, bool no_subqueries, bool onl
 		if (node->kind == ASTFunction::LAMBDA_EXPRESSION)
 			throw Exception("Unexpected expression", ErrorCodes::UNEXPECTED_EXPRESSION);
 
+		/// Функция arrayJoin.
 		if (node->kind == ASTFunction::ARRAY_JOIN)
 		{
 			if (node->arguments->children.size() != 1)
 				throw Exception("arrayJoin requires exactly 1 argument", ErrorCodes::TYPE_MISMATCH);
+
 			ASTPtr arg = node->arguments->children.at(0);
 			getActionsImpl(arg, no_subqueries, only_consts, actions_stack);
 			if (!only_consts)
@@ -1810,13 +1831,17 @@ void ExpressionAnalyzer::initChain(ExpressionActionsChain & chain, const NamesAn
 	}
 }
 
+/// "Большой" ARRAY JOIN.
 void ExpressionAnalyzer::addMultipleArrayJoinAction(ExpressionActionsPtr & actions) const
 {
 	NameSet result_columns;
 	for (const auto & result_source : array_join_result_to_source)
 	{
+		/// Дать столбцам новые имена, если надо.
 		if (result_source.first != result_source.second)
 			actions->add(ExpressionAction::copyColumn(result_source.second, result_source.first));
+
+		/// Сделать ARRAY JOIN (заменить массивы на их внутренности) для столбцов в этими новыми именами.
 		result_columns.insert(result_source.first);
 	}