Package com.mckoi.database
Class QueryPlan.JoinNode
- java.lang.Object
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- com.mckoi.database.QueryPlan.BranchQueryPlanNode
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- com.mckoi.database.QueryPlan.JoinNode
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- All Implemented Interfaces:
QueryPlanNode
,java.io.Serializable
,java.lang.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:
- Serialized Form
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Field Summary
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Fields inherited from class com.mckoi.database.QueryPlan.BranchQueryPlanNode
left, right
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Constructor Summary
Constructors Constructor Description JoinNode(QueryPlanNode left, QueryPlanNode right, Variable left_var, Operator join_op, Expression right_expression)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description java.lang.Object
clone()
Deep clone.java.util.ArrayList
discoverCorrelatedVariables(int level, java.util.ArrayList list)
Default implementation that discovers correlated variables for the given offset level.java.util.ArrayList
discoverTableNames(java.util.ArrayList list)
Default implementation delegates responsibility to children.Table
evaluate(QueryContext context)
Evaluates the node and returns the result as a Table.java.lang.String
titleString()
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Methods inherited from class com.mckoi.database.QueryPlan.BranchQueryPlanNode
debugString, left, right
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Constructor Detail
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JoinNode
public JoinNode(QueryPlanNode left, QueryPlanNode right, Variable left_var, Operator join_op, Expression right_expression)
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Method Detail
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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
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discoverTableNames
public java.util.ArrayList discoverTableNames(java.util.ArrayList list)
Description copied from class:QueryPlan.BranchQueryPlanNode
Default implementation delegates responsibility to children.- Specified by:
discoverTableNames
in interfaceQueryPlanNode
- Overrides:
discoverTableNames
in classQueryPlan.BranchQueryPlanNode
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discoverCorrelatedVariables
public java.util.ArrayList discoverCorrelatedVariables(int level, java.util.ArrayList list)
Description copied from class:QueryPlan.BranchQueryPlanNode
Default implementation that discovers correlated variables for the given offset level.- Specified by:
discoverCorrelatedVariables
in interfaceQueryPlanNode
- Overrides:
discoverCorrelatedVariables
in classQueryPlan.BranchQueryPlanNode
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clone
public java.lang.Object clone() throws java.lang.CloneNotSupportedException
Description copied from class:QueryPlan.BranchQueryPlanNode
Deep clone.- Specified by:
clone
in interfaceQueryPlanNode
- Overrides:
clone
in classQueryPlan.BranchQueryPlanNode
- Throws:
java.lang.CloneNotSupportedException
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titleString
public java.lang.String titleString()
- Overrides:
titleString
in classQueryPlan.BranchQueryPlanNode
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