Struct ExecutionPlanCache 

pub struct ExecutionPlanCache { /* private fields */ }

Cache for query execution plans.

This cache stores not just SQL strings but also execution hints and performance metrics for each query, enabling adaptive optimization.

Example

use prax_query::cache::{ExecutionPlanCache, PlanHint};

let cache = ExecutionPlanCache::new(1000);

// Register a plan with an index hint
let plan = cache.register(
    "find_user_by_email",
    "SELECT * FROM users WHERE email = $1",
    PlanHint::IndexScan("idx_users_email".into()),
);

// Get the plan later
if let Some(plan) = cache.get("find_user_by_email") {
    println!("Using plan with hint: {:?}", plan.hint);
}

Implementations

impl ExecutionPlanCache

pub fn new(max_size: usize) -> Self

Create a new execution plan cache.

pub fn register( &self, key: impl Into<Cow<'static, str>>, sql: impl AsRef<str>, hint: PlanHint, ) -> Arc<ExecutionPlan>

Register a new execution plan.

pub fn register_with_cost( &self, key: impl Into<Cow<'static, str>>, sql: impl AsRef<str>, hint: PlanHint, cost: f64, ) -> Arc<ExecutionPlan>

Register a plan with estimated cost.

pub fn get(&self, key: &str) -> Option<Arc<ExecutionPlan>>

Get a cached execution plan.

pub fn get_by_hash(&self, hash: u64) -> Option<Arc<ExecutionPlan>>

Get a plan by its hash.

pub fn get_or_register<F>( &self, key: impl Into<Cow<'static, str>>, sql_fn: F, hint: PlanHint, ) -> Arc<ExecutionPlan>

where F: FnOnce() -> String,

Get or create a plan.

pub fn record_execution(&self, key: &str, duration_us: u64)

Record execution timing for a plan.

pub fn slowest_queries(&self, limit: usize) -> Vec<Arc<ExecutionPlan>>

Get plans sorted by average execution time (slowest first).

pub fn most_used(&self, limit: usize) -> Vec<Arc<ExecutionPlan>>

Get plans sorted by use count (most used first).

pub fn clear(&self)

Clear all cached plans.

pub fn len(&self) -> usize

Get the number of cached plans.

pub fn is_empty(&self) -> bool

Check if the cache is empty.

Trait Implementations

impl Debug for ExecutionPlanCache

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

Formats the value using the given formatter.