| UINT_16 | DataFrame.IO.Parquet.Thrift |
| UINT_32 | DataFrame.IO.Parquet.Thrift |
| UINT_64 | DataFrame.IO.Parquet.Thrift |
| UINT_8 | DataFrame.IO.Parquet.Thrift |
| UnaggregatedException | DataFrame, DataFrame.Errors |
| unboxedOrFallback | DataFrame.Operations.Typing |
| UnboxedPageDecoder | DataFrame.IO.Parquet.Page |
| UnclosedQuotePolicy | DataFrame.IO.CSV |
| UNCOMPRESSED | DataFrame.IO.Parquet.Thrift |
| uncurry3 | DataFrame.IO.Utils.RandomAccess |
| unField | DataFrame.IO.Parquet.Thrift |
| union | |
| 1 (Function) | DataFrame |
| 2 (Function) | DataFrame.Typed, DataFrame.Typed.Operations |
| UniqueLeft | DataFrame.Typed.Schema |
| UNORDERED | DataFrame.IO.Parquet.Thrift |
| unsafeCast | DataFrame.Functions |
| unsafeCastExpr | |
| 1 (Function) | DataFrame.Typed, DataFrame.Typed.Expr, DataFrame.Typed.Lazy |
| 2 (Function) | DataFrame.Functions |
| unsafeFreeze | DataFrame.Typed, DataFrame.Typed.Freeze |
| unsafeParseTime | DataFrame.Operations.Typing |
| unsafeToByteString | DataFrame.IO.Utils.RandomAccess |
| unTDF | DataFrame.Typed.Lazy, DataFrame.Typed.Types |
| unTExpr | DataFrame.Typed, DataFrame.Typed.Expr, DataFrame.Typed.Lazy, DataFrame.Typed.Types |
| unTGD | DataFrame.Typed.Lazy, DataFrame.Typed.Types |
| UseFirstRow | DataFrame, DataFrame.IO.CSV |
| useLinearSolver | DataFrame, DataFrame.DecisionTree |
| userType | DataFrame, DataFrame.Errors |
| utcTimeToInt96 | DataFrame.IO.Parquet.Time |
| UTF8 | DataFrame.IO.Parquet.Thrift |
| UUIDType | |
| 1 (Type/Class) | DataFrame.IO.Parquet.Thrift |
| 2 (Data Constructor) | DataFrame.IO.Parquet.Thrift |