{
    "_yql_row_spec"={
        "Type"=["StructType";[
            ["k";["OptionalType";["DataType";"Int64"]]];
            ["v";["OptionalType";["DataType";"Int64"]]]]
        ];
    };

    "schema" = <"strict" = %true; "unique_keys" = %false>
    [
        {
            "name" = "k";
            "type" = "int64";
            "type_v3" = {"type_name" = "optional"; item = "int64"}
        };
        {
            "name" = "v";
            "type" = "int64";
            "type_v3" = {"type_name" = "optional"; item = "int64"}
        };
    ];
    "extended_stats" = [
        {
            "column_name" = "k";
            "data_weight" = 12;
            "num_unique_vals" = 3;
        };
        {
            "column_name" = "v";
            "data_weight" = 12;
            "num_unique_vals" = 3;
        }
    ];
}