Trait datagen::relation::KeyAttribute

pub trait KeyAttribute: Sized + 'static {
    fn null_key() -> Self;
    fn try_from_usize(x: usize) -> Result<Self>;
}

Specifies that the type is suitable to be a join, grouping, or partitioning key.

A key attribute is a primitive type (e.g., an integer or floating point type). It reserves a NULL value in it’s value range and usize values map to a unique key value.

The NULL value is expected to have a binary representation of all ones. For signed integers, that value equals -1, for unsigned integers, the value equals 0xF…F.

The NULL value in Rust must be kept in sync with the NULL value in C++ and CUDA.

Required methods

fn null_key() -> Self

fn try_from_usize(x: usize) -> Result<Self>

Implementations on Foreign Types

impl KeyAttribute for i32

fn null_key() -> Self

fn try_from_usize(x: usize) -> Result<Self>

impl KeyAttribute for i64

fn null_key() -> Self

fn try_from_usize(x: usize) -> Result<Self>

Implementors