Documentation

Options for reading Parquet data.

These options are applied in this order:

1. predicate filtering
2. column projection
3. row range

Column selection for selectedColumns uses leaf column names only.

Default Parquet read options.

Equivalent to:

ParquetReadOptions
    { selectedColumns = Nothing
    , predicate = Nothing
    , rowRange = Nothing
    }

Read a parquet file from path and load it into a dataframe.

Example

ghci> D.readParquet "./data/mtcars.parquet"

Read a Parquet file using explicit read options.

Example

ghci> D.readParquetWithOpts
ghci|   (D.defaultParquetReadOptions{D.selectedColumns = Just ["id"], D.rowRange = Just (0, 10)})
ghci|   ".testsdata/alltypes_plain.parquet"

Read Parquet files from a directory or glob path.

This is equivalent to calling readParquetFilesWithOpts with defaultParquetReadOptions.

Read multiple Parquet files (directory or glob) using explicit options.

If path is a directory, all non-directory entries are read. If path is a glob, matching files are read.

For multi-file reads, rowRange is applied once after concatenation (global range semantics).

Example

ghci> D.readParquetFilesWithOpts
ghci|   (D.defaultParquetReadOptions{D.selectedColumns = Just ["id"], D.rowRange = Just (0, 5)})
ghci|   ".testsdata/alltypes_plain*.parquet"