Struct Usage 

pub struct Usage {
    pub enabled: bool,
    pub reads: BTreeMap<String, Option<BTreeSet<String>>>,
    pub bound: BTreeMap<String, BTreeSet<String>>,
    pub indexed: BTreeSet<TableReference>,
}

What the query reads and binds, from its conditions and COLUMNS: what decides which edges are expanded through the graph index (see the module docs). The default plans joins, as a pattern was planned before.

Fields

enabled: bool

Whether the rest was found: if not, every edge is joined and every node too.

reads: BTreeMap<String, Option<BTreeSet<String>>>

Per variable, the properties the query reads of it: None for all of them (v.*). A variable that is not listed is not read.

bound: BTreeMap<String, BTreeSet<String>>

Per variable with a condition on it alone that limits a property to values the query names (v.p = 1, v.p IN (…)), those properties.

indexed: BTreeSet<TableReference>

The edge tables whose index is kept between queries: the ones fixed edges may be expanded on. Empty: every edge is joined.

Trait Implementations

impl Clone for Usage

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Usage

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

Formats the value using the given formatter.

impl Default for Usage

fn default() -> Self

Returns the “default value” for a type.

impl PartialEq for Usage

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Usage