Trait HashKey 

pub trait HashKey:
    EstimateSize
    + Clone
    + Debug
    + Hash
    + Eq
    + Sized
    + Send
    + Sync
    + 'static {
    type Bitmap: NullBitmap;

    // Required methods
    fn build_many(column_indices: &[usize], data_chunk: &DataChunk) -> Vec<Self>;
    fn deserialize(&self, data_types: &[DataType]) -> ArrayResult<OwnedRow>;
    fn deserialize_to_builders(
        &self,
        array_builders: &mut [ArrayBuilderImpl],
        data_types: &[DataType],
    ) -> ArrayResult<()>;
    fn null_bitmap(&self) -> &Self::Bitmap;
}

Trait for different kinds of hash keys.

Current comparison implementation treats null == null. This is consistent with postgresql’s group by implementation, but not join. In pg’s join implementation, null != null, and the join executor should take care of this.

Required Associated Types

type Bitmap: NullBitmap

Required Methods

fn build_many(column_indices: &[usize], data_chunk: &DataChunk) -> Vec<Self>

Build hash keys from the given data_chunk with column_indices in a batch.

fn deserialize(&self, data_types: &[DataType]) -> ArrayResult<OwnedRow>

Deserializes the hash key into a row.

fn deserialize_to_builders( &self, array_builders: &mut [ArrayBuilderImpl], data_types: &[DataType], ) -> ArrayResult<()>

Deserializes the hash key into array builders.

fn null_bitmap(&self) -> &Self::Bitmap

Get the null bitmap of the hash key.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl<S: KeyStorage, N: NullBitmap> HashKey for HashKeyImpl<S, N>

type Bitmap = N