Struct HopWindowStart 

pub struct HopWindowStart { /* private fields */ }

Computes the earliest hopping window start for a given timestamp.

hop(timestamp, slide, size) returns the start of the earliest window (of the given size, sliding by slide) that contains ts.

Limitation

This returns only the earliest window start. Full multi-window assignment (one row per window) is handled by Ring 0 operators.

Arguments

• Arg 0: Timestamp column or scalar
• Arg 1: Slide interval scalar
• Arg 2: Window size interval scalar

Implementations

impl HopWindowStart

pub fn new() -> Self

Creates a new hop window start UDF.

Trait Implementations

impl Debug for HopWindowStart

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

Formats the value using the given formatter.

impl Default for HopWindowStart

fn default() -> Self

Returns the “default value” for a type.

impl Hash for HopWindowStart

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 for HopWindowStart

fn eq(&self, _other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

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

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

impl ScalarUDFImpl for HopWindowStart

fn as_any(&self) -> &dyn Any

Returns this object as an Any trait object

fn name(&self) -> &'static str

Returns this function’s name

fn signature(&self) -> &Signature

Returns a [Signature] describing the argument types for which this function has an implementation, and the function’s Volatility.

fn return_type(&self, _arg_types: &[DataType]) -> Result<DataType>

[DataType] returned by this function, given the types of the arguments.

fn invoke_with_args(&self, args: ScalarFunctionArgs) -> Result<ColumnarValue>

Invoke the function returning the appropriate result.

fn aliases(&self) -> &[String]

Returns any aliases (alternate names) for this function.

fn display_name(&self, args: &[Expr]) -> Result<String, DataFusionError>

👎Deprecated since 50.0.0:

This method is unused and will be removed in a future release

Returns the user-defined display name of function, given the arguments

fn schema_name(&self, args: &[Expr]) -> Result<String, DataFusionError>

Returns the name of the column this expression would create

fn with_updated_config(&self, _config: &ConfigOptions) -> Option<ScalarUDF>

Create a new instance of this function with updated configuration.

fn return_field_from_args( &self, args: ReturnFieldArgs<'_>, ) -> Result<Arc<Field>, DataFusionError>

What type will be returned by this function, given the arguments?

fn is_nullable(&self, _args: &[Expr], _schema: &dyn ExprSchema) -> bool

👎Deprecated since 45.0.0:

Use return_field_from_args instead. if you use is_nullable that returns non-nullable with return_type, you would need to switch to return_field_from_args, you might have error

fn simplify( &self, args: Vec<Expr>, _info: &dyn SimplifyInfo, ) -> Result<ExprSimplifyResult, DataFusionError>

Optionally apply per-UDF simplification / rewrite rules.

fn short_circuits(&self) -> bool

Returns true if some of this exprs subexpressions may not be evaluated and thus any side effects (like divide by zero) may not be encountered.

fn conditional_arguments<'a>( &self, args: &'a [Expr], ) -> Option<(Vec<&'a Expr>, Vec<&'a Expr>)>

Determines which of the arguments passed to this function are evaluated eagerly and which may be evaluated lazily.

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

Computes the output [Interval] for a [ScalarUDFImpl], given the input intervals.

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

Updates bounds for child expressions, given a known [Interval]s for this function.

fn output_ordering( &self, inputs: &[ExprProperties], ) -> Result<SortProperties, DataFusionError>

Calculates the [SortProperties] of this function based on its children’s properties.

fn preserves_lex_ordering( &self, _inputs: &[ExprProperties], ) -> Result<bool, DataFusionError>

Returns true if the function preserves lexicographical ordering based on the input ordering.

fn coerce_types( &self, _arg_types: &[DataType], ) -> Result<Vec<DataType>, DataFusionError>

Coerce arguments of a function call to types that the function can evaluate.

fn documentation(&self) -> Option<&Documentation>

Returns the documentation for this Scalar UDF.

impl Eq for HopWindowStart