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

Variants§

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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.

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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

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Rle

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

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BitPacked

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

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DeltaBinaryPacked

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

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DeltaLengthByteArray

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

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DeltaByteArray

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

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RleDictionary

Dictionary encoding: the ids are encoded using the RLE encoding

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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.

Trait Implementations§

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more
Converts to this type from the input type.
Feeds this value into the given Hasher. Read more
Feeds a slice of this type into the given Hasher. Read more
This method tests for self and other values to be equal, and is used by ==.
This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
The type returned in the event of a conversion error.
Performs the conversion.

Auto Trait Implementations§

Blanket Implementations§

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.