Struct Hint

pub struct Hint {
    pub stats: Option<Stats>,
    pub constraint: Option<RuntimeConstraint>,
    pub alias: String,
    pub output_names: Vec<String>,
    pub advanced_extension: Option<AdvancedExtension>,
    pub saved_computations: Vec<SavedComputation>,
    pub loaded_computations: Vec<LoadedComputation>,
}

Changes to the operation that can influence efficiency/performance but should not impact correctness.

Fields

stats: Option<Stats>

constraint: Option<RuntimeConstraint>

alias: String

Name (alias) for this relation. Can be used for e.g. qualifying the relation (see e.g. Spark’s SubqueryAlias), or debugging.

output_names: Vec<String>

Assigns alternative output field names for any relation. Equivalent to the names field in RelRoot but applies to the output of the relation this RelCommon is attached to.

advanced_extension: Option<AdvancedExtension>

saved_computations: Vec<SavedComputation>

Save or load a system-specific computation for use in optimizing a remote operation. The anchor refers to the source/destination of the computation. The computation type and number refer to the current relation.

loaded_computations: Vec<LoadedComputation>

Trait Implementations

impl Clone for Hint

fn clone(&self) -> Hint

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Hint

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

Formats the value using the given formatter.

impl Default for Hint

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Hint

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

where D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Message for Hint

fn encoded_len(&self) -> usize

Returns the encoded length of the message without a length delimiter.

fn clear(&mut self)

Clears the message, resetting all fields to their default.

fn encode(&self, buf: &mut impl BufMut) -> Result<(), EncodeError>

where Self: Sized,

Encodes the message to a buffer.

fn encode_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message to a newly allocated buffer.

fn encode_length_delimited( &self, buf: &mut impl BufMut, ) -> Result<(), EncodeError>

where Self: Sized,

Encodes the message with a length-delimiter to a buffer.

fn encode_length_delimited_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message with a length-delimiter to a newly allocated buffer.

fn decode(buf: impl Buf) -> Result<Self, DecodeError>

where Self: Default,

Decodes an instance of the message from a buffer.

fn decode_length_delimited(buf: impl Buf) -> Result<Self, DecodeError>

where Self: Default,

Decodes a length-delimited instance of the message from the buffer.

fn merge(&mut self, buf: impl Buf) -> Result<(), DecodeError>

where Self: Sized,

Decodes an instance of the message from a buffer, and merges it into self.

fn merge_length_delimited(&mut self, buf: impl Buf) -> Result<(), DecodeError>

where Self: Sized,

Decodes a length-delimited instance of the message from buffer, and merges it into self.

impl PartialEq for Hint

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

Tests for self and other values to be equal, and is used by ==.

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

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

impl Serialize for Hint

fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>

where S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Hint