Statistics
https://play.clickhouse.com/play?user=play#c2VsZWN0IAp0b1N0YXJ0T2ZIb3VyKGNoZWNrX3N0YXJ0X3RpbWUpIGFzIGQsCmNvdW50KCksICBncm91cFVuaXFBcnJheShwdWxsX3JlcXVlc3RfbnVtYmVyKSwgIGFueShyZXBvcnRfdXJsKQpmcm9tIGNoZWNrcyB3aGVyZSAnMjAyMi0wNi0wMScgPD0gY2hlY2tfc3RhcnRfdGltZSBhbmQgdGVzdF9uYW1lIGxpa2UgJyUwMjQ5MV9wYXJ0X2xvZ19oYXNfdGFibGVfdXVpZCUnIGFuZCB0ZXN0X3N0YXR1cyBpbiAoJ0ZBSUwnLCAnRkxBS1knKSBncm91cCBieSBkIG9yZGVyIGJ5IGQgZGVzYw==

Some times there are not output from requests.
Row partition_row(fields_count);
    if (fields_count == 0)
    {
        
        assert(!partition_ast.fields_count);
        assert(typeid_cast<ASTFunction *>(partition_ast.value.get()));
        assert(partition_ast.value->as<ASTFunction>()->name == "tuple");
        assert(partition_ast.value->as<ASTFunction>()->arguments);
        auto args = partition_ast.value->as<ASTFunction>()->arguments;
        if (!args)
            throw Exception(ErrorCodes::BAD_ARGUMENTS, "Expected at least one argument in partition AST");
        bool empty_tuple = partition_ast.value->as<ASTFunction>()->arguments->children.empty();
        if (!empty_tuple)
            throw Exception(ErrorCodes::INVALID_PARTITION_VALUE, "Partition key is empty, expected 'tuple()' as partition key");
    }
    else if (fields_count == 1)
    {
        ASTPtr partition_value_ast = partition_ast.value;
        if (auto * tuple = partition_value_ast->as<ASTFunction>())
        {
            assert(tuple->name == "tuple");
            assert(tuple->arguments);
            assert(tuple->arguments->children.size() == 1);
            partition_value_ast = tuple->arguments->children[0];
        }
        
        Field partition_key_value = evaluateConstantExpression(partition_value_ast, local_context).first;
        partition_row[0] = convertFieldToTypeOrThrow(partition_key_value, *key_sample_block.getByPosition(0).type);
    }
    else