Module operators 

Query operators for streaming execution.

This module provides Volcano-style operators that implement streaming execution for SQL queries. Each operator implements the Operator trait with open(), next(), close() lifecycle.

Available Operators

Join Operators

• HashJoinOperator - Streaming hash join with O(N+M) complexity
• MergeJoinOperator - Merge join for pre-sorted inputs with O(N+M) complexity
• NestedLoopJoinOperator - Fallback for complex conditions with O(N*M) complexity
• IndexNestedLoopJoinOperator - Index-based join with O(N*log M) complexity
• BatchIndexNestedLoopJoinOperator - Batch variant for NO LIMIT queries

Algorithm Selection

Condition	Recommended Operator
Equality keys, large tables	HashJoinOperator
Both inputs pre-sorted	MergeJoinOperator
Inner table has index	IndexNestedLoopJoinOperator
No LIMIT + index available	BatchIndexNestedLoopJoinOperator
Non-equality conditions	NestedLoopJoinOperator
CROSS JOIN	NestedLoopJoinOperator

Note

For filtering and projection, use the Result Wrapper pattern:

• FilteredResult with RowFilter for WHERE clauses
• StreamingProjectionResult for column projection

See executor/result.rs and expression/evaluator_bridge.rs for the recommended execution model.

Re-exports

pub use crate::operator::ColumnSource;

pub use crate::operator::JoinProjection;

pub use bloom_filter::BloomFilterOperator;

pub use count_integer_antijoin::CountIntegerAntiJoinOperator;

pub use count_integer_antijoin::IntegerAntiJoinLookup;

pub use count_pk_semijoin::CountPkSemiJoinOperator;

pub use hash_join::HashJoinOperator;

pub use hash_join::JoinSide;

pub use hash_join::JoinType;

pub use index_nested_loop::BatchIndexNestedLoopJoinOperator;

pub use index_nested_loop::IndexLookupStrategy;

pub use index_nested_loop::IndexNestedLoopJoinOperator;

pub use merge_join::MergeJoinOperator;

pub use nested_loop_join::NestedLoopJoinOperator;

Modules

bloom_filter

Bloom filter operator for pre-join filtering.

count_integer_antijoin

Count-only integer anti-join.

count_pk_semijoin

Count-only unique PK semi-join.

hash_join

Streaming hash join operator.

index_nested_loop

Index Nested Loop Join Operator.

merge_join

Merge Join Operator for pre-sorted inputs.

nested_loop_join

Nested Loop Join Operator.