Enum parquet_format::Encoding

pub enum Encoding {
    Plain,
    PlainDictionary,
    Rle,
    BitPacked,
    DeltaBinaryPacked,
    DeltaLengthByteArray,
    DeltaByteArray,
    RleDictionary,
    ByteStreamSplit,
}

Encodings supported by Parquet. Not all encodings are valid for all types. These enums are also used to specify the encoding of definition and repetition levels. See the accompanying doc for the details of the more complicated encodings.

Variants

Plain

Default encoding. BOOLEAN - 1 bit per value. 0 is false; 1 is true. INT32 - 4 bytes per value. Stored as little-endian. INT64 - 8 bytes per value. Stored as little-endian. FLOAT - 4 bytes per value. IEEE. Stored as little-endian. DOUBLE - 8 bytes per value. IEEE. Stored as little-endian. BYTE_ARRAY - 4 byte length stored as little endian, followed by bytes. FIXED_LEN_BYTE_ARRAY - Just the bytes.

PlainDictionary

Deprecated: Dictionary encoding. The values in the dictionary are encoded in the plain type. in a data page use RLE_DICTIONARY instead. in a Dictionary page use PLAIN instead

Rle

Group packed run length encoding. Usable for definition/repetition levels encoding and Booleans (on one bit: 0 is false; 1 is true.)

BitPacked

Bit packed encoding. This can only be used if the data has a known max width. Usable for definition/repetition levels encoding.

DeltaBinaryPacked

Delta encoding for integers. This can be used for int columns and works best on sorted data

DeltaLengthByteArray

Encoding for byte arrays to separate the length values and the data. The lengths are encoded using DELTA_BINARY_PACKED

DeltaByteArray

Incremental-encoded byte array. Prefix lengths are encoded using DELTA_BINARY_PACKED. Suffixes are stored as delta length byte arrays.

RleDictionary

Dictionary encoding: the ids are encoded using the RLE encoding

ByteStreamSplit

Encoding for floating-point data. K byte-streams are created where K is the size in bytes of the data type. The individual bytes of an FP value are scattered to the corresponding stream and the streams are concatenated. This itself does not reduce the size of the data but can lead to better compression afterwards.

Implementations

impl Encoding

pub fn write_to_out_protocol(
    &self,
    o_prot: &mut dyn TOutputProtocol
) -> Result<()>

pub fn read_from_in_protocol(
    i_prot: &mut dyn TInputProtocol
) -> Result<Encoding>

Trait Implementations

impl Clone for Encoding

pub fn clone(&self) -> Encoding

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for Encoding

impl Debug for Encoding

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

Formats the value using the given formatter.

impl Eq for Encoding

impl Hash for Encoding

pub fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

pub fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl Ord for Encoding

pub fn cmp(&self, other: &Encoding) -> Ordering

This method returns an Ordering between self and other.

#[must_use]pub fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]pub fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]pub fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl PartialEq<Encoding> for Encoding

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

This method tests for self and other values to be equal, and is used by ==.

#[must_use]pub fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl PartialOrd<Encoding> for Encoding

pub fn partial_cmp(&self, other: &Encoding) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

#[must_use]pub fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

#[must_use]pub fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

#[must_use]pub fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

#[must_use]pub fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralEq for Encoding

impl StructuralPartialEq for Encoding

impl TryFrom<i32> for Encoding

type Error = Error

The type returned in the event of a conversion error.

pub fn try_from(i: i32) -> Result<Self, Self::Error>

Performs the conversion.