Struct PreparedSet 

pub struct PreparedSet;

A constant, non-null list whose elements are prepared as a set for membership lookups.

ListContains puts this in place of a literal list when an expression is optimized, so that every batch the expression is applied to looks up its needles in one shared PreparedSetData: the list is materialized, sorted and hashed once per expression rather than once per batch. In an array tree, the constant list of a ListContains node becomes this function with no children.

Every row of such an array holds the list. A slice or a filter of it keeps the options, so it looks up in the same set. A ListContainsElementReduce rule of the needle encoding can push the function into the needle’s parts with slices of the array, so that the chunks of a chunked needle all look up in one set, and a ListContainsElementKernel of the needle encoding gets the set through PreparedSet::set_of.

It serializes as the list, and deserializes into a set prepared again.

Implementations

impl PreparedSet

pub fn try_new_array(list: Scalar, len: usize) -> VortexResult<ArrayRef>

Prepares the non-null list scalar list as a set repeated len times.

ListContains prepares a constant list itself. A kernel crate can use this to test its ListContainsElementKernel against a prepared set.

Errors

Fails when list is not a list, or is null.

pub fn set_of(array: &ArrayRef) -> Option<&PreparedSetData>

The prepared set that every row of array holds, when array is a PreparedSet.

Trait Implementations

impl Clone for PreparedSet

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for PreparedSet

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

Formats the value using the given formatter.

impl ScalarFnVTable for PreparedSet

type Options = PreparedSetData

Options for this expression.

fn id(&self) -> ScalarFnId

Returns the ID of the scalar function vtable.

fn serialize(&self, set: &Self::Options) -> VortexResult<Option<Vec<u8>>>

Serialize the options for this expression.

fn deserialize( &self, metadata: &[u8], session: &VortexSession, ) -> VortexResult<Self::Options>

Deserialize the options of this expression.

fn arity(&self, _options: &Self::Options) -> Arity

Returns the arity of this expression.

fn child_name(&self, _options: &Self::Options, _child_idx: usize) -> ChildName

Returns the name of the nth child of the expr.

fn fmt_sql( &self, set: &Self::Options, _expr: &dyn ExprDisplay, f: &mut Formatter<'_>, ) -> Result

Format an expression tree in a human-readable SQL-style format.

fn return_dtype( &self, set: &Self::Options, _arg_dtypes: &[DType], ) -> VortexResult<DType>

Compute the return DType of the expression if evaluated over the given input types.

fn execute( &self, set: &Self::Options, args: &dyn ExecutionArgs, _ctx: &mut ExecutionCtx, ) -> VortexResult<ArrayRef>

Execute the expression over the input arguments.

fn validity<T: ReduceNode>( &self, _set: &Self::Options, node: &T, ) -> VortexResult<ReduceNodeValidity<T>>

For node, returns node’ which is exactly the result of evaluating validity(node). Returned node’ is either a lazy computation over children of node, a constant, or Irreducible which means you need to evaluate node to get its validity.

fn is_strict(&self, _options: &Self::Options) -> bool

Returns whether this scalar function is strict.

fn is_infallible(&self, _options: &Self::Options) -> bool

Returns whether this scalar function can never raise a semantic error.

fn reduce<T: ReduceNode>( &self, options: &Self::Options, node: &T, ) -> VortexResult<Option<T>>

Implement an abstract reduction rule over a tree of scalar functions.

fn simplify( &self, options: &Self::Options, expr: &BoundExpression, ) -> VortexResult<Option<BoundExpression>>

Simplify the bound expression if possible.