Struct RootDataType

pub struct RootDataType { /* private fields */ }

Represents the root data type of the ORC file. Contains multiple named child types which map to the columns available. Allows projecting only specific columns from the base schema.

This is essentially a Struct type, but with special handling such as for projection and transforming into an Arrow schema.

Note that the ORC spec states the root type does not necessarily have to be a Struct. Currently we only support having a Struct as the root data type.

See: https://orc.apache.org/docs/types.html

Implementations

impl RootDataType

pub fn column_index(&self) -> usize

Root column index is always 0.

pub fn children(&self) -> &[NamedColumn]

Base columns of the file.

pub fn create_arrow_schema( &self, user_metadata: &HashMap<String, String>, ) -> Schema

Convert into an Arrow schema.

pub fn project(&self, mask: &ProjectionMask) -> Self

Create new root data type based on mask of columns to project.

Trait Implementations

impl Clone for RootDataType

fn clone(&self) -> RootDataType

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for RootDataType

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for RootDataType

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.