Enum ColumnOrder 

pub enum ColumnOrder {
    TYPE_DEFINED_ORDER(SortOrder),
    IEEE_754_TOTAL_ORDER,
    INT96_TIMESTAMP_ORDER,
    UNDEFINED,
    UNKNOWN,
}

Column order that specifies what method was used to aggregate min/max values for statistics.

Prior to version 2.4.0, Parquet used signed comparisons when computing min and max values for statistics. This caused problems for UTF8 encoded strings, so the ColumnOrder union was added, initially with a single variant TYPE_ORDER. The sort order for columns was then defined based on the logical or physical type of the column, and could use either signed comparison, unsigned comparison, or for some types be left undefined. Since then several new ColumnOrders have been added to the specification.

In this crate, the ColumnOrder found in the footer is represented by this enum. To convey what actual sort order to use, this crate maps the ColumnOrder along with the physical and logical type to a SortOrder. It is this SortOrder that is used internally when deciding how to compute the min/max statistics.

If column order is undefined, then it is the legacy behaviour and all values should be compared as signed values/bytes.

Variants

TYPE_DEFINED_ORDER(SortOrder)

Column uses the order defined by its logical or physical type (if there is no logical type), parquet-format 2.4.0+.

IEEE_754_TOTAL_ORDER

Column ordering to use for floating point types.

INT96_TIMESTAMP_ORDER

Column ordering to use for INT96 types.

UNDEFINED

Undefined column order, means legacy behaviour before parquet-format 2.4.0. Sort order is always SIGNED.

UNKNOWN

An unknown but present ColumnOrder. Statistics with an unknown ColumnOrder will be ignored.

Implementations

impl ColumnOrder

pub fn column_order_for_type( logical_type: Option<&LogicalType>, converted_type: ConvertedType, physical_type: Type, ) -> ColumnOrder

Returns the ColumnOrder for a physical/logical type.

pub fn sort_order_for_type( logical_type: Option<&LogicalType>, converted_type: ConvertedType, physical_type: Type, is_type_defined: bool, ) -> SortOrder

👎Deprecated since 60.0.0:

use ColumnOrder::sort_order instead

Returns sort order for a physical/logical type.

is_type_defined indicates whether the column order for this type is ColumnOrder::TYPE_DEFINED_ORDER.

It is now preferred to obtain this via Self::sort_order.

pub(crate) fn get_sort_order_for_type( logical_type: Option<&LogicalType>, converted_type: ConvertedType, physical_type: Type, is_type_defined: bool, ) -> SortOrder

fn get_converted_sort_order( converted_type: ConvertedType, physical_type: Type, is_type_defined: bool, ) -> SortOrder

fn get_default_sort_order( physical_type: Type, is_type_defined: bool, ) -> SortOrder

Returns default sort order based on physical type.

pub fn sort_order(&self) -> SortOrder

Returns sort order associated with this column order.

Trait Implementations

impl Clone for ColumnOrder

fn clone(&self) -> ColumnOrder

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ColumnOrder

impl Debug for ColumnOrder

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

Formats the value using the given formatter.

impl Display for ColumnOrder

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

Formats the value using the given formatter.

impl Eq for ColumnOrder

impl HeapSize for ColumnOrder

fn heap_size(&self) -> usize

Return the size of any bytes allocated on the heap by this object, including heap memory in those structures

impl PartialEq for ColumnOrder

fn eq(&self, other: &ColumnOrder) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl<'a, R: ThriftCompactInputProtocol<'a>> ReadThrift<'a, R> for ColumnOrder

fn read_thrift(prot: &mut R) -> Result<Self>

Read an object of type Self from the input protocol object.

impl StructuralPartialEq for ColumnOrder

impl WriteThrift for ColumnOrder

const ELEMENT_TYPE: ElementType = ElementType::Struct

The ElementType to use when a list of this object is written.

fn write_thrift<W: Write>( &self, writer: &mut ThriftCompactOutputProtocol<W>, ) -> Result<()>

Serialize this object to the given writer.