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ColumnCodec

Enum ColumnCodec 

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#[repr(u8)]
pub enum ColumnCodec {
Show 16 variants Auto = 0, AlpFastLanesLz4 = 1, AlpRdLz4 = 2, PcodecLz4 = 3, DeltaFastLanesLz4 = 4, FastLanesLz4 = 5, FsstLz4 = 6, AlpFastLanesRans = 7, DeltaFastLanesRans = 8, FsstRans = 9, Gorilla = 10, DoubleDelta = 11, Delta = 12, Lz4 = 13, Zstd = 14, Raw = 15,
}
Expand description

Codec identifier for per-column compression selection.

Stored in partition schema metadata so the reader knows which decoder to use for each column file.

Variants§

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Auto = 0

Engine selects codec automatically based on column type and data distribution (analyzed at flush time).

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AlpFastLanesLz4 = 1

f64 metrics: ALP (decimal→int) → FastLanes → lz4.

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AlpRdLz4 = 2

f64 true doubles: ALP-RD (front-bit dict) → lz4.

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PcodecLz4 = 3

f64/i64 complex: Pcodec → lz4.

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DeltaFastLanesLz4 = 4

i64 timestamps/counters: Delta → FastLanes → lz4.

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FastLanesLz4 = 5

i64/u32 raw integers: FastLanes → lz4.

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FsstLz4 = 6

Strings/logs: FSST (substring dict) → lz4.

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AlpFastLanesRans = 7

f64 metrics cold: ALP → FastLanes → rANS.

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DeltaFastLanesRans = 8

i64 cold: Delta → FastLanes → rANS.

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FsstRans = 9

Strings cold: FSST → rANS.

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Gorilla = 10

Gorilla XOR encoding — f64 codec selected by detect.rs for float columns.

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DoubleDelta = 11

DoubleDelta — timestamp codec selected by detect.rs for monotonic timestamp columns.

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Delta = 12

Delta + varint — counter codec selected by detect.rs for integer delta columns.

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Lz4 = 13

LZ4 block compression — for string/log columns.

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Zstd = 14

Zstd — for cold/archived partitions.

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Raw = 15

No compression — for pre-compressed or symbol columns.

Implementations§

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impl ColumnCodec

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pub fn is_compressed(&self) -> bool

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pub fn is_cascading(&self) -> bool

Whether this is a cascading (multi-stage) codec.

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pub fn is_cold_tier(&self) -> bool

Whether this codec uses rANS as terminal (cold tier).

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pub fn as_str(&self) -> &'static str

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pub fn try_resolve(self) -> Result<ResolvedColumnCodec, CodecError>

Resolve Auto to a concrete codec using the provided detection result, or return an error if this is called with Auto where a concrete value is required (i.e. a caller forgot to run detection first).

For callers that have already run detection and hold a non-Auto codec, this is a zero-cost newtype wrap.

Trait Implementations§

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impl Clone for ColumnCodec

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fn clone(&self) -> ColumnCodec

Returns a duplicate of the value. Read more
1.0.0 (const: unstable) · Source§

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

Performs copy-assignment from source. Read more
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impl Debug for ColumnCodec

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

Formats the value using the given formatter. Read more
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impl<'de> Deserialize<'de> for ColumnCodec

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fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>
where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer. Read more
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impl Display for ColumnCodec

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

Formats the value using the given formatter. Read more
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impl<'__msgpack_de> FromMessagePack<'__msgpack_de> for ColumnCodec

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fn read<R: Read<'__msgpack_de>>(reader: &mut R) -> Result<Self, Error>
where Self: Sized,

Reads the MessagePack representation of this value from the provided reader.
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impl Hash for ColumnCodec

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

Feeds this value into the given Hasher. Read more
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fn hash_slice<H>(data: &[Self], state: &mut H)
where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher. Read more
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impl PartialEq for ColumnCodec

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

Tests for self and other values to be equal, and is used by ==.
1.0.0 (const: unstable) · Source§

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
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impl Serialize for ColumnCodec

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fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>
where __S: Serializer,

Serialize this value into the given Serde serializer. Read more
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impl ToMessagePack for ColumnCodec

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fn write<W: Write>(&self, writer: &mut W) -> Result<(), Error>

Writes the MessagePack representation of this value into the provided writer.
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impl Copy for ColumnCodec

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impl Eq for ColumnCodec

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impl StructuralPartialEq for ColumnCodec

Auto Trait Implementations§

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
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impl<T> CloneToUninit for T
where T: Clone,

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unsafe fn clone_to_uninit(&self, dest: *mut u8)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dest. Read more
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T, U> Into<U> for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

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

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impl<T> Same for T

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type Output = T

Should always be Self
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impl<SS, SP> SupersetOf<SS> for SP
where SS: SubsetOf<SP>,

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fn to_subset(&self) -> Option<SS>

The inverse inclusion map: attempts to construct self from the equivalent element of its superset. Read more
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fn is_in_subset(&self) -> bool

Checks if self is actually part of its subset T (and can be converted to it).
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fn to_subset_unchecked(&self) -> SS

Use with care! Same as self.to_subset but without any property checks. Always succeeds.
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fn from_subset(element: &SS) -> SP

The inclusion map: converts self to the equivalent element of its superset.
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impl<T> ToOwned for T
where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T> ToString for T
where T: Display + ?Sized,

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fn to_string(&self) -> String

Converts the given value to a String. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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impl<T> DeserializeOwned for T
where T: for<'de> Deserialize<'de>,

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impl<T> FromMessagePackOwned for T
where T: for<'a> FromMessagePack<'a>,

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impl<T> Scalar for T
where T: 'static + Clone + PartialEq + Debug,