21.11.3.6
```
cat /etc/clickhouse-server/node.tsv
1,test

cat /etc/clickhouse-server/node_dictionary.xml
<dictionaries>
    <dictionary>
        <name>node</name>
        <source>
            <file>
                <path>/etc/clickhouse-server/node.tsv</path>
                <format>CSV</format>
            </file>
        </source>
        <lifetime>0</lifetime>
        <layout><flat /></layout>
        <structure>
            <id><name>key</name></id>
            <attribute>
                <name>name</name>
                <type>String</type>
                <null_value></null_value>
            </attribute>
        </structure>
    </dictionary>
</dictionaries>

create table default.node ( key UInt64, name String ) Engine=Dictionary(node);

select * from default.node;
┌─key─┬─name─┐
│   1 │ test │
└─────┴──────┘

/etc/init.d/clickhouse-server restart

<Error> Application: DB::Exception: Cannot attach 1 tables due to cyclic dependencies. See server log for details.
<Information> Application: shutting down
```
else if (make_columns_nullable)
            {
                column_type = makeNullable(column_type);
            }
            column_names_and_types.emplace_back(col_decl.name, column_type);
        }
        else
        {
            
            column_names_and_types.emplace_back(col_decl.name, std::make_shared<DataTypeUInt8>());
        }
        
        if (col_decl.default_expression)
        {
            /** For columns with explicitly-specified type create two expressions:
              * 1. default_expression aliased as column name with _tmp suffix
              * 2. conversion of expression (1) to explicitly-specified type alias as column name
              */
            if (col_decl.type)
            {
                const auto & final_column_name = col_decl.name;
                const auto tmp_column_name = final_column_name + "_tmp_alter" + toString(randomSeed());
                const auto * data_type_ptr = column_names_and_types.back().type.get();
                default_expr_list->children.emplace_back(
                    setAlias(addTypeConversionToAST(std::make_shared<ASTIdentifier>(tmp_column_name), data_type_ptr->getName()),
                        final_column_name));
                default_expr_list->children.emplace_back(
                    setAlias(
                        col_decl.default_expression->clone(),
                        tmp_column_name));