Struct PlanCache 

pub struct PlanCache { /* private fields */ }

LRU cache for compiled physical plans.

The cache stores physical plans keyed by their logical plan fingerprint. When the cache is full, the least recently used entry is evicted.

Implementations

impl PlanCache

pub fn new(max_size: usize) -> Self

Creates a new plan cache with the given maximum size.

pub fn default_size() -> Self

Creates a plan cache with default size (64 entries).

pub fn get(&mut self, fingerprint: u64) -> Option<&PhysicalPlan>

Gets a cached plan by fingerprint, or returns None if not cached.

pub fn insert(&mut self, fingerprint: u64, plan: PhysicalPlan)

Inserts a plan into the cache. If the cache is full, evicts the least recently used entry.

pub fn get_or_insert_with<F>( &mut self, fingerprint: u64, compile: F, ) -> &PhysicalPlan

where F: FnOnce() -> PhysicalPlan,

Gets a cached plan or compiles and caches a new one.

pub fn clear(&mut self)

Clears the cache.

pub fn len(&self) -> usize

Returns the number of cached plans.

pub fn is_empty(&self) -> bool

Returns true if the cache is empty.

pub fn hits(&self) -> u64

Returns cache hit count.

pub fn misses(&self) -> u64

Returns cache miss count.

pub fn hit_rate(&self) -> f64

Returns cache hit rate (0.0 to 1.0).

pub fn invalidate_table(&mut self, _table: &str)

Invalidates all cached plans for a specific table. Call this when table schema or data changes significantly.