Planner.ExpressionPlan

java.lang.Object
- com.mckoi.database.interpret.Planner.ExpressionPlan

All Implemented Interfaces:

java.lang.Comparable

Direct Known Subclasses:

Planner.QueryTableSetPlanner.ComplexSingleExpressionPlan, Planner.QueryTableSetPlanner.ConstantExpressionPlan, Planner.QueryTableSetPlanner.ExhaustiveJoinExpressionPlan, Planner.QueryTableSetPlanner.ExhaustiveSelectExpressionPlan, Planner.QueryTableSetPlanner.ExhaustiveSubQueryExpressionPlan, Planner.QueryTableSetPlanner.SimplePatternExpressionPlan, Planner.QueryTableSetPlanner.SimpleSelectExpressionPlan, Planner.QueryTableSetPlanner.SimpleSingleExpressionPlan, Planner.QueryTableSetPlanner.SimpleSubQueryExpressionPlan, Planner.QueryTableSetPlanner.StandardJoinExpressionPlan, Planner.QueryTableSetPlanner.SubLogicExpressionPlan

Enclosing class:

Planner
```
abstract static class Planner.ExpressionPlan
extends java.lang.Object
implements java.lang.Comparable
```
An abstract class that represents an expression to be added into a plan. Many sets of expressions can be added into the plan tree in any order, however it is often desirable to add some more intensive expressions higher up the branches. This object allows us to order expressions by optimization value. More optimizable expressions are put near the leafs of the plan tree and least optimizable and put near the top.

Field Summary

Fields
Modifier and Type Field Description

private float optimizable_value
How optimizable an expression is.

Constructor Summary

Constructors
Constructor Description

ExpressionPlan()

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`abstract void`	`addToPlanTree()`	Adds this expression into the plan tree.
`int`	`compareTo(java.lang.Object ob)`
`float`	`getOptimizableValue()`	Returns the optimizable value for this plan.
`void`	`setOptimizableValue(float v)`	Sets the optimizable value of this plan.

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

- Field Detail
  - optimizable_value
```
private float optimizable_value
```
    How optimizable an expression is. A value of 0 indicates most optimizable and 1 indicates least optimizable.
- Constructor Detail
  - ExpressionPlan
```
ExpressionPlan()
```
- Method Detail
  - setOptimizableValue
```
public void setOptimizableValue(float v)
```
    Sets the optimizable value of this plan.
  - getOptimizableValue
```
public float getOptimizableValue()
```
    Returns the optimizable value for this plan.
  - addToPlanTree
```
public abstract void addToPlanTree()
```
    Adds this expression into the plan tree.
  - compareTo
```
public int compareTo(java.lang.Object ob)
```
    Specified by:
    
    compareTo in interface java.lang.Comparable