aiondb-optimizer

Lowers a LogicalPlan into a PhysicalPlan. Applies predicate pushdown, projection pruning, transitive-predicate inference, outer-join simplification, join reordering, access-path selection, and HNSW / vector-search planning. Costs are computed against catalog statistics fetched through a CatalogReader.

cargo

[dependencies]
aiondb-optimizer = { path = "../aiondb-optimizer" }

modules

module	purpose
`physical_builder`	Drives the logical-to-physical lowering and emits `PhysicalPlan` nodes.
`access_path`	Picks an access path for each scan (sequential, index lookup, index range, vector search).
`cost`	`PlanCost` and per-operator costing helpers.
`rules`	Logical-rewrite rules dispatched from the top of `optimize`.
`predicate_pushdown`	Pushes filters past joins and projections.
`projection_pruning`	Drops columns that downstream operators do not need.
`transitive_predicates`	Derives `a = b && b = c => a = c` style predicates to enable extra index lookups.
`outer_join_simplify`	Converts outer joins to inner joins where the outer side is provably non-null.
`join_reorder`	Reorders inner-join chains by estimated row count.
`graph_optimizer`	Cypher-specific rewrites.
`distributed`	Lowering for `DistributedPhysicalPlan` fragments.

key types

Optimizer - top-level optimizer, built with Optimizer::new(catalog_reader).
OptimizeRequest - input bundle: logical_plan and txn_id.
PlanCost (in cost) - rows + cpu + io estimate attached to candidate plans.
PhysicalBuilder (in physical_builder) - re-exported builder that walks a LogicalPlan and produces PhysicalPlan nodes.

entry points

item	role
`Optimizer::new(catalog)`	Build an optimizer over a `CatalogReader`.
`Optimizer::optimize(req)`	Lower a `LogicalPlan` to `PhysicalPlan`, returning a `DbResult<PhysicalPlan>`.
`Optimizer::optimize_cypher_with_stats(...)`	Cypher-specific optimization path that accepts external statistics.

example

use std::sync::Arc;
use aiondb_catalog::CatalogReader;
use aiondb_core::TxnId;
use aiondb_optimizer::{OptimizeRequest, Optimizer};
use aiondb_plan::LogicalPlan;

fn lower(catalog: Arc<dyn CatalogReader>, logical: LogicalPlan, txn: TxnId) {
    let optimizer = Optimizer::new(catalog);
    let req = OptimizeRequest {
        logical_plan: logical,
        txn_id: txn,
    };
    let physical = optimizer.optimize(req).expect("optimize");
    let _ = physical;
}