{
    "_yql_row_spec"={
        "Type"=["StructType";[
            ["Key1";["DataType";"Int32"]];
            ["Key2";["DataType";"String"]];
            ["Fk1";["OptionalType";["DataType";"String"]]];
            ["Value";["OptionalType";["DataType";"String"]]]]
        ];
        "SortDirections"=[1;1];
        "SortedBy"=["Key1";"Key2"];
        "SortedByTypes"=[["DataType";"Int32";];["DataType";"String"]];
        "SortMembers"=["Key1";"Key2"];
    };
    "schema" = <"strict" = %true; "unique_keys" = %false>
    [
        {
            "name" = "Key1";
            "sort_order" = "ascending";
            "type" = "int64";
            "type_v3" = {"type_name" = "optional"; item = "int64"}
        };
        {
            "name" = "Key2";
            "sort_order" = "ascending";
            "type" = "string";
            "type_v3" = {"type_name" = "optional"; item = "string"}
        };
        {
            "name" = "Fk1";
            "type" = "string";
            "type_v3" = {"type_name" = "optional"; item = "string"}
        };
        {
            "name" = "Value";
            "type" = "string";
            "type_v3" = {"type_name" = "optional"; item = "string"}
        };
    ];
    "extended_stats" = [
        {
            "column_name" = "Key1";
            "data_weight" = 56;
            "num_unique_vals" = 11;
        };
        {
            "column_name" = "Key2";
            "data_weight" = 66;
            "num_unique_vals" = 5;
        };
        {
            "column_name" = "Fk1";
            "data_weight" = 70;
            "num_unique_vals" = 5;
        };
        {
            "column_name" = "Value";
            "data_weight" = 98;
            "num_unique_vals" = 6;
        }
    ]
}