ydb/yt/yql/tests/sql/suites/schema/row_spec.txt.attr

{
    "_yql_row_spec"={"Type"=["StructType";[["a"; ["OptionalType"; ["DataType"; "Int64"]]]; ["b"; ["OptionalType"; ["DataType"; "Uint64"]]]; ["c"; ["OptionalType"; ["DataType"; "Double"]]]; ["d"; ["OptionalType"; ["DataType"; "String"]]]; ["e"; ["OptionalType"; ["DataType"; "Bool"]]]; ["f"; ["OptionalType"; ["DataType"; "Yson"]]]]]; "UniqueKeys"=%false}
}