Package dev.frostlake.executor.operators

Class JoinOperator

java.lang.Object

dev.frostlake.executor.operators.JoinOperator

All Implemented Interfaces:

Operator

public class JoinOperator
extends Object
implements Operator

JOIN operator - joins two sets of rows based on a condition. This operator supports multiple join types: - INNER JOIN: Returns rows when there's a match in both tables - LEFT JOIN: Returns all rows from left table, matched rows from right - RIGHT JOIN: Returns all rows from right table, matched rows from left - FULL JOIN: Returns all rows when there's a match in either table - CROSS JOIN: Returns Cartesian product of both tables

Constructor Summary

Constructors

Constructor	Description
JoinOperator(Table leftTable, Table rightTable, List<Row> rightRows, JoinType joinType, String joinCondition, JoinConditionEvaluator conditionEvaluator)	Create a JOIN operator with a condition evaluator.

Method Summary

Modifier and Type	Method	Description
static JoinOperator	cross(Table leftTable, Table rightTable, List<Row> rightRows)	Create a CROSS JOIN operator (no condition).
List<Row>	execute(List<Row> leftRows, OperatorContext context)	Execute this operator on the input rows.
String	getDescription()	Get a description of this operator for debugging/logging.
JoinOperator	withEquiKeys(int[] leftKeyIdx, int[] rightKeyIdx)	Enable hash-join candidate filtering using the given equi-join key column indices.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

JoinOperator

public JoinOperator(Table leftTable,
 Table rightTable,
 List<Row> rightRows,
 JoinType joinType,
 String joinCondition,
 JoinConditionEvaluator conditionEvaluator)

Create a JOIN operator with a condition evaluator.

Parameters:

leftTable - Left table metadata

rightTable - Right table metadata

rightRows - Rows from the right table

joinType - Type of join to perform

joinCondition - Join condition expression (null for CROSS JOIN)

conditionEvaluator - Evaluator to evaluate join condition on pair of rows (null for CROSS JOIN)

Method Details

cross

public static JoinOperator cross(Table leftTable,
 Table rightTable,
 List<Row> rightRows)

Create a CROSS JOIN operator (no condition).

withEquiKeys

public JoinOperator withEquiKeys(int[] leftKeyIdx,
 int[] rightKeyIdx)

Enable hash-join candidate filtering using the given equi-join key column indices.

execute

public List<Row> execute(List<Row> leftRows,
 OperatorContext context)

Description copied from interface: Operator

Execute this operator on the input rows.

Specified by:

execute in interface Operator

Parameters:

leftRows - The input rows from the previous operator

context - The execution context containing table metadata and other information

Returns:

The output rows after applying this operator

getDescription

public String getDescription()

Description copied from interface: Operator

Get a description of this operator for debugging/logging.

Specified by:

getDescription in interface Operator

Returns:

A human-readable description of the operator