Enum datafusion_expr::Volatility
source · [−]pub enum Volatility {
Immutable,
Stable,
Volatile,
}
Expand description
A function’s volatility, which defines the functions eligibility for certain optimizations
Variants
Immutable
Immutable - An immutable function will always return the same output when given the same input. An example of this is super::BuiltinScalarFunction::Cos.
Stable
Stable - A stable function may return different values given the same input across different queries but must return the same value for a given input within a query. An example of this is super::BuiltinScalarFunction::Now.
Volatile
Volatile - A volatile function may change the return value from evaluation to evaluation. Multiple invocations of a volatile function may return different results when used in the same query. An example of this is super::BuiltinScalarFunction::Random.
Trait Implementations
sourceimpl Clone for Volatility
impl Clone for Volatility
sourcefn clone(&self) -> Volatility
fn clone(&self) -> Volatility
Returns a copy of the value. Read more
1.0.0 · sourcefn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
Performs copy-assignment from source
. Read more
sourceimpl Debug for Volatility
impl Debug for Volatility
sourceimpl Hash for Volatility
impl Hash for Volatility
sourceimpl Ord for Volatility
impl Ord for Volatility
sourceimpl PartialEq<Volatility> for Volatility
impl PartialEq<Volatility> for Volatility
sourceimpl PartialOrd<Volatility> for Volatility
impl PartialOrd<Volatility> for Volatility
sourcefn partial_cmp(&self, other: &Volatility) -> Option<Ordering>
fn partial_cmp(&self, other: &Volatility) -> Option<Ordering>
This method returns an ordering between self
and other
values if one exists. Read more
1.0.0 · sourcefn lt(&self, other: &Rhs) -> bool
fn lt(&self, other: &Rhs) -> bool
This method tests less than (for self
and other
) and is used by the <
operator. Read more
1.0.0 · sourcefn le(&self, other: &Rhs) -> bool
fn le(&self, other: &Rhs) -> bool
This method tests less than or equal to (for self
and other
) and is used by the <=
operator. Read more
impl Copy for Volatility
impl Eq for Volatility
impl StructuralEq for Volatility
impl StructuralPartialEq for Volatility
Auto Trait Implementations
impl RefUnwindSafe for Volatility
impl Send for Volatility
impl Sync for Volatility
impl Unpin for Volatility
impl UnwindSafe for Volatility
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
T: ?Sized,
impl<T> BorrowMut<T> for T where
T: ?Sized,
const: unstable · sourcepub fn borrow_mut(&mut self) -> &mut T
pub fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more
sourceimpl<T> CallHasher for T where
T: Hash + ?Sized,
impl<T> CallHasher for T where
T: Hash + ?Sized,
sourceimpl<Q, K> Equivalent<K> for Q where
Q: Eq + ?Sized,
K: Borrow<Q> + ?Sized,
impl<Q, K> Equivalent<K> for Q where
Q: Eq + ?Sized,
K: Borrow<Q> + ?Sized,
sourcepub fn equivalent(&self, key: &K) -> bool
pub fn equivalent(&self, key: &K) -> bool
Compare self to key
and return true
if they are equal.
sourceimpl<T> ToOwned for T where
T: Clone,
impl<T> ToOwned for T where
T: Clone,
type Owned = T
type Owned = T
The resulting type after obtaining ownership.
sourcepub fn to_owned(&self) -> T
pub fn to_owned(&self) -> T
Creates owned data from borrowed data, usually by cloning. Read more
sourcepub fn clone_into(&self, target: &mut T)
pub fn clone_into(&self, target: &mut T)
toowned_clone_into
)Uses borrowed data to replace owned data, usually by cloning. Read more