Struct PartitionHint 

pub struct PartitionHint {
    pub strategies: Vec<i32>,
    pub count: i64,
}

Enhancement that hints the executor how to partition a relation’s output.

Attach this to any standard relation via register_enhancement to convey partitioning decisions made during planning.

Text Format

=== Plan
Root[result]
  Read[data => col:i64]
    + Enh:PartitionHint[&HASH, count=8]

Fields

strategies: Vec<i32>

The strategies to apply, in order of preference. Each value is the integer representation of PartitionStrategy.

count: i64

Target number of partitions. 0 means “let the executor decide”.

Implementations

impl PartitionHint

pub fn strategies( &self, ) -> FilterMap<Cloned<Iter<'_, i32>>, fn(i32) -> Option<PartitionStrategy>>

Returns an iterator which yields the valid enum values contained in strategies.

pub fn push_strategies(&mut self, value: PartitionStrategy)

Appends the provided enum value to strategies.

Trait Implementations

impl Clone for PartitionHint

fn clone(&self) -> PartitionHint

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PartitionHint

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

Formats the value using the given formatter.

impl Default for PartitionHint

fn default() -> Self

Returns the “default value” for a type.

impl Explainable for PartitionHint

fn name() -> &'static str

Canonical textual name for this extension. This is what appears in Substrait text plans and how the registry identifies the type.

fn from_args(args: &ExtensionArgs) -> Result<Self, ExtensionError>

Parse extension arguments into this type

fn to_args(&self) -> Result<ExtensionArgs, ExtensionError>

Convert this type to extension arguments

impl Message for PartitionHint

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 Name for PartitionHint

const PACKAGE: &'static str = "example"

Package name this message type is contained in. They are domain-like and delimited by ., e.g. google.protobuf.

const NAME: &'static str = "PartitionHint"

Simple name for this Message. This name is the same as it appears in the source .proto file, e.g. FooBar.

fn full_name() -> String

Fully-qualified unique name for this Message. It’s prefixed with the package name and names of any parent messages, e.g. google.rpc.BadRequest.FieldViolation. By default, this is the package name followed by the message name. Fully-qualified names must be unique within a domain of Type URLs.

fn type_url() -> String

Type URL for this Message, which by default is the full name with a leading slash, but may also include a leading domain name, e.g. type.googleapis.com/google.profile.Person. This can be used when serializing into the google.protobuf.Any type.

impl PartialEq for PartitionHint

fn eq(&self, other: &PartitionHint) -> 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 StructuralPartialEq for PartitionHint