Struct DefaultSchemaAdapter 

pub(crate) struct DefaultSchemaAdapter {
    projected_table_schema: SchemaRef,
}

This SchemaAdapter requires both the table schema and the projected table schema. See SchemaMapping for more details

Fields

projected_table_schema: SchemaRef

The schema for the table, projected to include only the fields being output (projected) by the associated ParquetSource

Trait Implementations

impl Clone for DefaultSchemaAdapter

fn clone(&self) -> DefaultSchemaAdapter

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DefaultSchemaAdapter

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

Formats the value using the given formatter.

impl SchemaAdapter for DefaultSchemaAdapter

fn map_column_index(&self, index: usize, file_schema: &Schema) -> Option<usize>

Map a column index in the table schema to a column index in a particular file schema

Panics if index is not in range for the table schema

fn map_schema( &self, file_schema: &Schema, ) -> Result<(Arc<dyn SchemaMapper>, Vec<usize>)>

Creates a SchemaMapping for casting or mapping the columns from the file schema to the table schema.

If the provided file_schema contains columns of a different type to the expected table_schema, the method will attempt to cast the array data from the file schema to the table schema where possible.

Returns a SchemaMapping that can be applied to the output batch along with an ordered list of columns to project from the file