Struct TableSet 

pub struct TableSet { /* private fields */ }

A set of table indices.

Implementations

impl TableSet

pub fn new() -> Self

The empty set, which is what a constant reads.

pub fn of(index: u32) -> Self

The set holding one index.

pub fn insert(&mut self, index: u32)

Adds an index.

pub fn contains(&self, index: u32) -> bool

Whether the index is in the set.

pub fn is_empty(&self) -> bool

Whether the set holds nothing, which is what a predicate over no column reads.

pub fn extend(&mut self, other: &Self)

Adds everything in other.

pub fn is_subset_of(&self, other: &Self) -> bool

Whether everything in this set is also in other.

The question filter pushdown asks of every predicate at every join. An empty set is a subset of everything, which is the right answer for a predicate that reads no column: it gives the same answer wherever it is evaluated.

Trait Implementations

impl Clone for TableSet

fn clone(&self) -> TableSet

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for TableSet

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

Formats the value using the given formatter.

impl Default for TableSet

fn default() -> TableSet

Returns the “default value” for a type.

impl Eq for TableSet

impl PartialEq for TableSet

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for TableSet