Struct QueryHints 

pub struct QueryHints {
    pub join_hints: Vec<JoinHint>,
    pub index_hints: Vec<IndexHint>,
    pub cardinality_hints: Vec<CardinalityHint>,
    pub parallelism_hints: Option<ParallelismHint>,
    pub materialization_hints: Vec<MaterializationHint>,
    pub timeout_hint: Option<Duration>,
    pub memory_hint: Option<MemoryHint>,
    pub cache_hints: Option<CacheHint>,
    pub join_order_hint: Option<JoinOrderHint>,
    pub filter_hints: Vec<FilterHint>,
    pub custom_directives: HashMap<String, String>,
}

Query hints for optimizer guidance

Fields

join_hints: Vec<JoinHint>

Join algorithm hints

index_hints: Vec<IndexHint>

Index usage hints

cardinality_hints: Vec<CardinalityHint>

Cardinality override hints

parallelism_hints: Option<ParallelismHint>

Parallelism configuration hints

materialization_hints: Vec<MaterializationHint>

Materialization strategy hints

timeout_hint: Option<Duration>

Query timeout hint

memory_hint: Option<MemoryHint>

Memory limit hint

cache_hints: Option<CacheHint>

Cache control hints

join_order_hint: Option<JoinOrderHint>

Ordering hints for join execution

filter_hints: Vec<FilterHint>

Filter pushdown hints

custom_directives: HashMap<String, String>

Custom optimizer directives

Implementations

impl QueryHints

pub fn new() -> Self

Create new empty hints

pub fn builder() -> QueryHintsBuilder

Create hints builder

pub fn is_empty(&self) -> bool

Check if any hints are specified

pub fn hint_count(&self) -> usize

Get hint count

pub fn merge(&mut self, other: QueryHints)

Merge hints from another QueryHints instance (other takes precedence)

pub fn get_join_hint(&self, vars: &[Variable]) -> Option<&JoinHint>

Get join hint for specific variables

pub fn get_cardinality_hint(&self, var: &Variable) -> Option<u64>

Get cardinality hint for a variable

pub fn get_index_hint(&self, pattern_id: &str) -> Option<&IndexHint>

Get index hint for a pattern

Trait Implementations

impl Clone for QueryHints

fn clone(&self) -> QueryHints

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for QueryHints

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

Formats the value using the given formatter.

impl Default for QueryHints

fn default() -> QueryHints

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for QueryHints

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for QueryHints

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.