pub enum RelationalJoinSelectivity {
Unknown,
EquiJoin {
left_distinct_values: Option<u64>,
right_distinct_values: Option<u64>,
},
}Variants§
Unknown
No trustworthy predicate statistics are available. Materialized joins use the documented 10% fallback; probe inputs ignore this value because their row estimate is already a per-outer-row fanout.
EquiJoin
Distinct-value counts for the complete equality key on either side.
One known side is still a useful conservative denominator; when both
sides are known, the standard 1 / max(left_ndv, right_ndv) estimate is
used.
Implementations§
Trait Implementations§
Source§impl Clone for RelationalJoinSelectivity
impl Clone for RelationalJoinSelectivity
Source§fn clone(&self) -> RelationalJoinSelectivity
fn clone(&self) -> RelationalJoinSelectivity
Returns a duplicate of the value. Read more
1.0.0 (const: unstable) · Source§fn clone_from(&mut self, source: &Self)
fn clone_from(&mut self, source: &Self)
Performs copy-assignment from
source. Read moreimpl Copy for RelationalJoinSelectivity
Source§impl Debug for RelationalJoinSelectivity
impl Debug for RelationalJoinSelectivity
Source§impl Default for RelationalJoinSelectivity
impl Default for RelationalJoinSelectivity
Source§fn default() -> RelationalJoinSelectivity
fn default() -> RelationalJoinSelectivity
Returns the “default value” for a type. Read more
impl Eq for RelationalJoinSelectivity
impl StructuralPartialEq for RelationalJoinSelectivity
Auto Trait Implementations§
impl Freeze for RelationalJoinSelectivity
impl RefUnwindSafe for RelationalJoinSelectivity
impl Send for RelationalJoinSelectivity
impl Sync for RelationalJoinSelectivity
impl Unpin for RelationalJoinSelectivity
impl UnsafeUnpin for RelationalJoinSelectivity
impl UnwindSafe for RelationalJoinSelectivity
Blanket Implementations§
Source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
Source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more