Module executor 

Query Executor v2 - Index-Aware Execution Engine

解决 v1 Executor 的性能问题：

• v1: ScanNode 全表扫描构建节点集合 -> O(N)
• v2: 智能索引扫描 + Index Nested Loop Join -> O(log N)

关键改进：

1. NodeScan 使用 Hexastore 索引而不是全表扫描
2. Index Nested Loop Join 避免内存爆炸
3. 基础统计信息支持 Join 顺序优化

Structs

ArcExecutionContext

Arc-based execution context for true streaming across FFI boundary This allows iterators to hold a reference to the database without lifetime issues

ExecutionContext

OwnedExecutionContext

Owned execution context for FFI - uses raw pointer to avoid lifetime issues SAFETY: The caller must ensure db_ptr remains valid for the lifetime of this context

Record

ScanStats

节点扫描统计信息

Enums

Value

Traits

ExecutionPlan

Functions

evaluate_expression_value