Struct QueryPlanner 

pub struct QueryPlanner { /* private fields */ }

Stateful planner wrapper that memoizes query plans by SQL template and schema cookie.

The caller is responsible for supplying a stable SQL template string for the query shape being planned. Literal normalization, placeholder canonicalization, and any higher-level SQL parsing remain above this crate’s current scope.

Implementations

impl QueryPlanner

pub fn new() -> Self

Construct a planner with the default 128-entry LRU plan cache.

pub fn with_plan_cache_capacity(capacity: usize) -> Self

Construct a planner with a caller-provided cache capacity.

A zero capacity is clamped to 1 so callers can tune the cache without dealing with NonZeroUsize.

pub fn plan_cache_len(&self) -> usize

Return the number of cached plans currently retained.

pub fn is_plan_cache_empty(&self) -> bool

Return true when no cached plans are currently retained.

pub fn clear_plan_cache(&mut self)

Clear all cached plans and forget the schema cookie they were built under.

pub fn cached_plan<F>( &mut self, sql_template: &str, schema_cookie: u32, build: F, ) -> Rc<QueryPlan>

where F: FnOnce() -> QueryPlan,

Return a cached plan for the given SQL template and schema cookie, or compute one.

When the schema cookie changes, the entire cache is flushed because any DDL may invalidate earlier planning decisions.

pub fn order_joins_with_cache( &mut self, sql_template: &str, schema_cookie: u32, tables: &[TableStats], indexes: &[IndexInfo], where_terms: &[WhereTerm<'_>], needed_columns: Option<&[String]>, cross_join_pairs: &[(String, String)], table_index_hints: Option<&BTreeMap<String, IndexHint>>, cracking_hints: Option<&mut CrackingHintStore>, feature_flags: PlannerFeatureFlags, ) -> Rc<QueryPlan>

Cached wrapper around order_joins_with_hints_and_features.

This preserves the current stateless free-function API while exposing a planner-local cache for repeated SELECT templates.

Trait Implementations

impl Debug for QueryPlanner

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

Formats the value using the given formatter.

impl Default for QueryPlanner

fn default() -> Self

Returns the “default value” for a type.