Struct datafusion_physical_expr::expressions::Column

pub struct Column { /* private fields */ }

Represents the column at a given index in a RecordBatch

Implementations

impl Column

pub fn new(name: &str, index: usize) -> Self

Create a new column expression

pub fn new_with_schema(name: &str, schema: &Schema) -> Result<Self>

Create a new column expression based on column name and schema

pub fn name(&self) -> &str

Get the column name

pub fn index(&self) -> usize

Get the column index

Trait Implementations

impl Clone for Column

fn clone(&self) -> Column

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Column

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

Formats the value using the given formatter.

impl Display for Column

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

Formats the value using the given formatter.

impl Hash for Column

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq<Column> for Column

fn eq(&self, other: &Column) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<dyn Any> for Column

fn eq(&self, other: &dyn Any) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PhysicalExpr for Column

fn as_any(&self) -> &dyn Any

Return a reference to Any that can be used for downcasting

fn data_type(&self, input_schema: &Schema) -> Result<DataType>

Get the data type of this expression, given the schema of the input

fn nullable(&self, input_schema: &Schema) -> Result<bool>

Decide whehter this expression is nullable, given the schema of the input

fn evaluate(&self, batch: &RecordBatch) -> Result<ColumnarValue>

Evaluate the expression

fn children(&self) -> Vec<Arc<dyn PhysicalExpr>>

Get a list of child PhysicalExpr that provide the input for this expr.

fn with_new_children( self: Arc<Self>, _children: Vec<Arc<dyn PhysicalExpr>> ) -> Result<Arc<dyn PhysicalExpr>>

Returns a new PhysicalExpr where all children were replaced by new exprs.

fn dyn_hash(&self, state: &mut dyn Hasher)

Update the hash state with this expression requirements from Hash.

fn evaluate_selection( &self, batch: &RecordBatch, selection: &BooleanArray ) -> Result<ColumnarValue>

Evaluate an expression against a RecordBatch after first applying a validity array

fn evaluate_bounds(&self, _children: &[&Interval]) -> Result<Interval>

Computes bounds for the expression using interval arithmetic.

fn propagate_constraints( &self, _interval: &Interval, _children: &[&Interval] ) -> Result<Vec<Option<Interval>>>

Updates/shrinks bounds for the expression using interval arithmetic. If constraint propagation reveals an infeasibility, returns None for the child causing infeasibility. If none of the children intervals change, may return an empty vector instead of cloning children.

fn get_ordering(&self, _children: &[SortProperties]) -> SortProperties

The order information of a PhysicalExpr can be estimated from its children. This is especially helpful for projection expressions. If we can ensure that the order of a PhysicalExpr to project matches with the order of SortExec, we can eliminate that SortExecs.

impl Eq for Column

impl StructuralEq for Column

impl StructuralPartialEq for Column