Module optimizer 

Rule-based SQL query optimizer for LogicalPlan.

The optimizer applies a configurable sequence of rewrite passes to a LogicalPlan tree. Each pass implements OptPass and is applied in order. The default pipeline (built by Optimizer::new) includes:

1. PredicatePushdown — push filters toward leaf scans
2. ProjectionPruning — trim projections to the required column set
3. ConstantFolding — evaluate literal expressions at compile time
4. LimitPushThrough — push LIMIT N into single-table scans
5. JoinAlgorithmPass — annotate Join nodes with an algorithm hint

Re-exports

pub use cse::CommonSubexprElimination;

pub use join_algo::JoinAlgoHint;

pub use join_algo::JoinAlgorithmPass;

pub use simplify::PredicateSimplification;

Modules

cse

Common-subexpression-elimination pass.

expr_util

Shared expression utilities for optimizer passes.

join_algo

Pass 5: Join algorithm selection.

join_reorder

Cost-based join reordering pass (Item 1).

simplify

Predicate-simplification pass.

Structs

ConstantFolding

Evaluate constant expressions in Filter predicates at compile time.

LimitPushThrough

Push a Limit node down into a single-table Scan.

Optimizer

Multi-pass rule-based optimizer.

PredicatePushdown

Push Filter nodes toward leaf Scan nodes.

ProjectionPruning

Prune Project column lists to only those columns required by the parent.

Traits

OptPass

A single optimizer rewrite rule.

Functions

optimize

Run all five default optimizer passes over plan.