| I16 | DataFrame.IO.Parquet.Thrift | 
| I32 | DataFrame.IO.Parquet.Thrift | 
| I64 | DataFrame.IO.Parquet.Thrift | 
| ICSV | DataFrame.Lazy.Internal.DataFrame, DataFrame.Lazy | 
| If |   | 
| 1 (Type/Class) | DataFrame.Internal.Types | 
| 2 (Data Constructor) | DataFrame.Internal.Expression | 
| ifilterColumn | DataFrame.Internal.Column | 
| ifoldlColumn | DataFrame.Internal.Column | 
| ifoldrColumn | DataFrame.Internal.Column | 
| ifThenElse | DataFrame.Functions | 
| imapColumn | DataFrame.Internal.Column | 
| impute | DataFrame.Operations.Transformations, DataFrame | 
| INDEX_PAGE | DataFrame.IO.Parquet.Types | 
| INDEX_PAGE_HEADER | DataFrame.IO.Parquet.Types | 
| InferFromSample | DataFrame.IO.CSV, DataFrame | 
| InferredType | DataFrame.IO.CSV | 
| inferType | DataFrame.IO.CSV | 
| inferTypes | DataFrame.Lazy.IO.CSV | 
| inferValueType | DataFrame.Lazy.IO.CSV | 
| initializeColumns | DataFrame.IO.CSV | 
| INNER | DataFrame.Operations.Join, DataFrame | 
| innerJoin | DataFrame.Operations.Join, DataFrame | 
| inputPath | DataFrame.Lazy.Internal.DataFrame, DataFrame.Lazy | 
| InputType | DataFrame.Lazy.Internal.DataFrame, DataFrame.Lazy | 
| inputType | DataFrame.Lazy.Internal.DataFrame, DataFrame.Lazy | 
| insertColumn | DataFrame.Operations.Core, DataFrame | 
| insertUnboxedVector | DataFrame.Operations.Core, DataFrame | 
| insertVector | DataFrame.Operations.Core, DataFrame | 
| insertVectorWithDefault | DataFrame.Operations.Core, DataFrame | 
| int96ToUTCTime | DataFrame.IO.Parquet.Time | 
| IntegralIf | DataFrame.Internal.Types | 
| IntegralTypes | DataFrame.Internal.Types | 
| InternalException | DataFrame.Errors, DataFrame | 
| interpret | DataFrame.Internal.Expression | 
| interpretAggregation | DataFrame.Internal.Expression | 
| interQuartileRange | DataFrame.Operations.Statistics, DataFrame | 
| interQuartileRange' | DataFrame.Internal.Statistics | 
| intIsSigned | DataFrame.IO.Parquet.Types | 
| IntType |   | 
| 1 (Data Constructor) | DataFrame.IO.Parquet.Types | 
| 2 (Data Constructor) | DataFrame.IO.CSV | 
| isAdjustedToUTC | DataFrame.IO.Parquet.Types | 
| isColumnMaxValueExact |   | 
| 1 (Function) | DataFrame.IO.Parquet.ColumnStatistics | 
| 2 (Function) | DataFrame.IO.Parquet.Types | 
| isColumnMinValueExact |   | 
| 1 (Function) | DataFrame.IO.Parquet.ColumnStatistics | 
| 2 (Function) | DataFrame.IO.Parquet.Types | 
| isCommutative | DataFrame.Internal.Expression | 
| isDataPage | DataFrame.IO.Parquet.Page | 
| isDictionaryPage | DataFrame.IO.Parquet.Page | 
| isHaskellIdentifier | DataFrame.Functions | 
| isLiteral | DataFrame.Functions | 
| isNull | DataFrame.IO.CSV | 
| isNullish | DataFrame.Internal.Parsing | 
| isNumeric | DataFrame.Internal.Column, DataFrame | 
| isNumericColumn |   | 
| 1 (Function) | DataFrame.Display.Web.Plot | 
| 2 (Function) | DataFrame.Display.Terminal.Plot, DataFrame | 
| isNumericColumnCheck |   | 
| 1 (Function) | DataFrame.Display.Web.Plot | 
| 2 (Function) | DataFrame.Display.Terminal.Plot, DataFrame | 
| isReservedId | DataFrame.Functions | 
| isVarId | DataFrame.Functions |