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
```
{
    assert(global_context == global_context->getGlobalContext());
    TableLoadingDependenciesVisitor::Data data;
    data.default_database = global_context->getCurrentDatabase();
    data.create_query = ast;
    data.global_context = global_context;
    TableLoadingDependenciesVisitor visitor{data};
    visitor.visit(ast);
    return data.dependencies;
}
void DDLDependencyVisitor::visit(const ASTPtr & ast, Data & data)
{
    
    if (const auto * function = ast->as<ASTFunction>())
        visit(*function, data);
    else if (const auto * dict_source = ast->as<ASTFunctionWithKeyValueArguments>())
        visit(*dict_source, data);
    else if (const auto * storage = ast->as<ASTStorage>())
        visit(*storage, data);
}
bool DDLDependencyVisitor::needChildVisit(const ASTPtr & node, const ASTPtr & child)