Trait Operator

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pub trait Operator:
    'static
    + Send
    + Sync
    + Debug
    + DynOperatorHash
    + DynOperatorEq {
Show 16 methods    // Required methods
    fn id(&self) -> OperatorId;
    fn as_any(&self) -> &dyn Any;
    fn dtype(&self) -> &DType;
    fn bounds(&self) -> LengthBounds;
    fn children(&self) -> &[OperatorRef] ⓘ;
    fn with_children(
        self: Arc<Self>,
        _children: Vec<OperatorRef>,
    ) -> VortexResult<OperatorRef>;

    // Provided methods
    fn len(&self) -> Option<usize> { ... }
    fn is_empty(&self) -> bool { ... }
    fn nchildren(&self) -> usize { ... }
    fn fmt_as(&self, _df: DisplayFormat, f: &mut Formatter<'_>) -> Result { ... }
    fn fmt_all(&self) -> String { ... }
    fn reduce_children(&self) -> VortexResult<Option<OperatorRef>> { ... }
    fn reduce_parent(
        &self,
        _parent: OperatorRef,
        _child_idx: usize,
    ) -> VortexResult<Option<OperatorRef>> { ... }
    fn is_selection_target(&self, _child_idx: usize) -> Option<bool> { ... }
    fn as_batch(&self) -> Option<&dyn BatchOperator> { ... }
    fn as_pipelined(&self) -> Option<&dyn PipelinedOperator> { ... }
}

Expand description

An operator represents a node in a logical query plan.

Required Methods§

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fn id(&self) -> OperatorId

The unique identifier for this operator instance.

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fn as_any(&self) -> &dyn Any

For downcasting.

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fn dtype(&self) -> &DType

Returns the DType of the array produced by this operator.

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fn bounds(&self) -> LengthBounds

Returns the bounds on the number of rows produced by this operator.

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fn children(&self) -> &[OperatorRef] ⓘ

The children of this operator.

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fn with_children( self: Arc<Self>, _children: Vec<OperatorRef>, ) -> VortexResult<OperatorRef>

Create a new instance of this operator with the given children.

§Panics

Panics if the number or dtypes of children are incorrect.

Provided Methods§

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fn len(&self) -> Option<usize>

Returns the exact number of rows produced by this operator, if known.

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fn is_empty(&self) -> bool

Returns if this operator is known to be empty (i.e. max bound is 0).

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fn nchildren(&self) -> usize

The number of children of this operator.

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

Override the default formatting of this operator.

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fn fmt_all(&self) -> String

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fn reduce_children(&self) -> VortexResult<Option<OperatorRef>>

Attempt to optimize this node by analyzing its children.

For example, if all the children are constant, this function should perform constant folding and return a constant operator.

This function should typically be implemented only for self-contained optimizations based on child properties

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fn reduce_parent( &self, _parent: OperatorRef, _child_idx: usize, ) -> VortexResult<Option<OperatorRef>>

Attempt to push down a parent operator through this node.

The child_idx parameter indicates which child of the parent this operator occupies. For example, if the parent is a binary operator, and this operator is the left child, then child_idx will be 0. If this operator is the right child, then child_idx will be 1.

The returned operator will replace the parent in the tree.

This function should typically be implemented for cross-operator optimizations where the child needs to adapt to the parent’s requirements

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fn is_selection_target(&self, _child_idx: usize) -> Option<bool>

Return true if the given child is considered to be a selection target.

The definition of this is such that pushing a selection operator down to all selection targets will result in the same output as a selection on this operator.

For example, select(Op, mask) == Op(select(child, mask), ...) for all children that are selection targets.

If any child index returns None, then selection pushdown is not possible. If all children return Some(false), then selection pushdown is not possible.

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