Enum Volatility 

pub enum Volatility {
    Immutable,
    Stable,
    Volatile,
}

Volatility classification of a UDF (S3).

Mirrors DataFusion / Spark’s Volatility enum so the optimizer can decide whether constant-folding, predicate pushdown, and result caching are safe.

Variants

Immutable

Always returns the same output for the same input. Default.

Stable

Returns the same output for the same input within a single query (e.g. a function that reads a session-scoped parameter).

Volatile

May return a different value on every invocation. current_timestamp, rand, uuid etc. The optimizer must not fold or cache the result.

Trait Implementations

impl Clone for Volatility

fn clone(&self) -> Volatility

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Volatility

impl Debug for Volatility

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

Formats the value using the given formatter.

impl Default for Volatility

fn default() -> Volatility

Returns the “default value” for a type.

impl Eq for Volatility

impl Hash for Volatility

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 Volatility

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Volatility