java.lang.Object

com.mckoi.database.QueryPlan.BranchQueryPlanNode

com.mckoi.database.QueryPlan.JoinNode

All Implemented Interfaces:: QueryPlanNode, Serializable, Cloneable

Enclosing class:: QueryPlan

public static class QueryPlan.JoinNode extends QueryPlan.BranchQueryPlanNode

A branch node for a non-equi join between two tables.

NOTE: The cost of a LeftJoin is higher if the right child result is greater than the left child result. The plan should be arranged so smaller results are on the left.

See Also:

Field Summary

Fields inherited from class com.mckoi.database.QueryPlan.BranchQueryPlanNode
left, right
Constructor Summary

Constructors

Constructor

Description

JoinNode(QueryPlanNode left, QueryPlanNode right, Variable left_var, Operator join_op, Expression right_expression)
Method Summary

Modifier and Type

Method

Description

Object

clone()

Deep clone.

ArrayList

discoverCorrelatedVariables(int level, ArrayList list)

Default implementation that discovers correlated variables for the given offset level.

ArrayList

discoverTableNames(ArrayList list)

Default implementation delegates responsibility to children.

Table

evaluate(QueryContext context)

Evaluates the node and returns the result as a Table.

String

titleString()

Methods inherited from class com.mckoi.database.QueryPlan.BranchQueryPlanNode
debugString, left, right

Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details
- JoinNode
  
  public JoinNode(QueryPlanNode left, QueryPlanNode right, Variable left_var, Operator join_op, Expression right_expression)
Method Details
- evaluate
  
  public Table evaluate(QueryContext context)
  
  Description copied from interface: QueryPlanNode
  
  Evaluates the node and returns the result as a Table. The VariableResolver resolves any outer variables
- discoverTableNames
  
  public ArrayList discoverTableNames(ArrayList list)
  
  Description copied from class: QueryPlan.BranchQueryPlanNode
  
  Default implementation delegates responsibility to children.
  
  Specified by:
  
  discoverTableNames in interface QueryPlanNode
  
  Overrides:
  
  discoverTableNames in class QueryPlan.BranchQueryPlanNode
- discoverCorrelatedVariables
  
  public ArrayList discoverCorrelatedVariables(int level, ArrayList list)
  
  Description copied from class: QueryPlan.BranchQueryPlanNode
  
  Default implementation that discovers correlated variables for the given offset level.
  
  Specified by:
  
  discoverCorrelatedVariables in interface QueryPlanNode
  
  Overrides:
  
  discoverCorrelatedVariables in class QueryPlan.BranchQueryPlanNode
- clone
  
  public Object clone() throws CloneNotSupportedException
  
  Description copied from class: QueryPlan.BranchQueryPlanNode
  
  Deep clone.
  
  Specified by:
  
  clone in interface QueryPlanNode
  
  Overrides:
  
  clone in class QueryPlan.BranchQueryPlanNode
  
  Throws:
  
  CloneNotSupportedException
- titleString
  
  public String titleString()
  
  Overrides:
  
  titleString in class QueryPlan.BranchQueryPlanNode

Class QueryPlan.JoinNode

Field Summary

Fields inherited from class com.mckoi.database.QueryPlan.BranchQueryPlanNode

Constructor Summary

Method Summary

Methods inherited from class com.mckoi.database.QueryPlan.BranchQueryPlanNode

Methods inherited from class java.lang.Object

Constructor Details

JoinNode

Method Details

evaluate

discoverTableNames

discoverCorrelatedVariables

clone

titleString