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read_column

exporter

Function read_column 

Source 
pub(crate) fn read_column<T: DataType>(
    row_group: &dyn RowGroupReader,
    index: usize,
) -> Result<Vec<T::T>>
Expand description

Reads every value of one required column in a row group.

Reads in batches of up to the row group’s row count until the reader returns no more records. Definition and repetition levels are not read, so this is only correct for REQUIRED columns, which is what the archive schema uses.

§Arguments

  • row_group - Row group to read from.
  • index - Column index within the row group.

§Errors

Returns an error if the column reader cannot be created or decoding fails.

§Panics

Panics (inside the parquet crate) if the column’s physical type does not match T.