Planner data structures shared between SQL parsing and execution.

The crate exposes:

• plan_graph for the serialized DAG representation exchanged with tooling.
• plans for high-level logical plan structures emitted by the SQL layer.
• validation helpers that enforce naming and schema invariants while plans are being assembled.
• conversion utilities for converting SQL AST nodes to Plan types.
• traversal generic iterative traversal utilities for deeply nested ASTs.

Modules are re-exported so downstream crates can use llkv_plan::* when they only need a subset of the functionality.

LLKV Plan

llkv-plan defines the typed plan surface that bridges parsed SQL and LLKV runtime execution. It organizes statement plans, expression programs, and subquery metadata so lower layers can execute without re-parsing SQL.

This crate is not intended for direct standalone use.

License

Licensed under the Apache-2.0 License.