Costs (flink 1.0-SNAPSHOT API)

java.lang.Object
- org.apache.flink.optimizer.costs.Costs

All Implemented Interfaces:

Cloneable, Comparable<Costs>
```
public class Costs
extends Object
implements Comparable<Costs>, Cloneable
```
Simple class to represent the costs of an operation. The costs are currently tracking, network, I/O and CPU costs. Costs are composed of two parts of cost contributors:
1. Quantifiable costs. Those costs are used when estimates are available and track a quantifiable measure, such as the number of bytes for network or I/O
2. Heuristic costs. Those costs are used when no estimates are available. They can be used to track that an operator used a special operation which is heuristically considered more expensive than another operation.
The quantifiable costs may frequently be unknown, which is represented by a -1 as a value for the unknown components of the cost. In that case, all operations' costs are unknown and hence it is not decidable which operation to favor during pruning. In that case, the heuristic costs should contain a value to make sure that operators with different strategies are comparable, even in the absence of estimates. The heuristic costs are hence the system's mechanism of realizing pruning heuristics that favor some operations over others.

Field Summary

Fields
Modifier and Type Field and Description

static double UNKNOWN

Fields
Modifier and Type	Field and Description
`static double`	`UNKNOWN`

Constructor Summary

Constructors
Constructor and Description
`Costs()` Default constructor.
`Costs(double networkCost, double diskCost)` Creates a new costs object using the given values for the network and storage cost.
`Costs(double networkCost, double diskCost, double cpuCost)` Creates a new costs object using the given values for the network and storage cost.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`addCosts(Costs other)` Adds the given costs to these costs.
`void`	`addCpuCost(double cost)` Adds the given CPU cost to the current CPU cost for this Costs object.
`void`	`addDiskCost(double bytes)` Adds the costs for disk to the current disk costs for this Costs object.
`void`	`addHeuristicCpuCost(double cost)` Adds the given heuristic CPU cost to the current heuristic CPU cost for this Costs object.
`void`	`addHeuristicDiskCost(double cost)` Adds the heuristic costs for disk to the current heuristic disk costs for this Costs object.
`void`	`addHeuristicNetworkCost(double cost)` Adds the heuristic costs for network to the current heuristic network costs for this Costs object.
`void`	`addNetworkCost(double bytes)` Adds the costs for network to the current network costs for this Costs object.
`Costs`	`clone()`
`int`	`compareTo(Costs o)` The order of comparison is: network first, then disk, then CPU.
`void`	`divideBy(int factor)`
`boolean`	`equals(Object obj)`
`double`	`getCpuCost()` Gets the cost for the CPU.
`double`	`getDiskCost()` Gets the costs for disk.
`double`	`getHeuristicCpuCost()` Gets the heuristic cost for the CPU.
`double`	`getHeuristicDiskCost()` Gets the heuristic costs for disk.
`double`	`getHeuristicNetworkCost()` Gets the heuristic network cost.
`double`	`getNetworkCost()` Gets the network cost.
`int`	`hashCode()`
`void`	`multiplyWith(int factor)`
`void`	`setCpuCost(double cost)` Sets the cost for the CPU.
`void`	`setDiskCost(double bytes)` Sets the costs for disk for this Costs object.
`void`	`setHeuristicCpuCost(double cost)` Sets the heuristic cost for the CPU.
`void`	`setHeuristicDiskCost(double cost)` Sets the heuristic costs for disk for this Costs object.
`void`	`setHeuristicNetworkCost(double cost)` Sets the heuristic network cost for this Costs object.
`void`	`setNetworkCost(double bytes)` Sets the network cost for this Costs object.
`void`	`subtractCosts(Costs other)` Subtracts the given costs from these costs.
`String`	`toString()`

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

- Field Detail
  - UNKNOWN
```
public static final double UNKNOWN
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - Costs
```
public Costs()
```
    Default constructor. Initializes all costs to 0;
  - Costs
```
public Costs(double networkCost,
             double diskCost)
```
    Creates a new costs object using the given values for the network and storage cost.
    
    Parameters:
    
    networkCost - The network cost, in bytes to be transferred.
    
    diskCost - The cost for disk, in bytes to be written and read.
  - Costs
```
public Costs(double networkCost,
             double diskCost,
             double cpuCost)
```
    Creates a new costs object using the given values for the network and storage cost.
    
    Parameters:
    
    networkCost - The network cost, in bytes to be transferred.
    
    diskCost - The cost for disk, in bytes to be written and read.
    
    cpuCost - The cost for CPU operations.
- Method Detail
  - getNetworkCost
```
public double getNetworkCost()
```
    Gets the network cost.
    
    Returns:
    
    The network cost, in bytes to be transferred.
  - setNetworkCost
```
public void setNetworkCost(double bytes)
```
    Sets the network cost for this Costs object.
    
    Parameters:
    
    bytes - The network cost to set, in bytes to be transferred.
  - addNetworkCost
```
public void addNetworkCost(double bytes)
```
    Adds the costs for network to the current network costs for this Costs object.
    
    Parameters:
    
    bytes - The network cost to add, in bytes to be transferred.
  - getDiskCost
```
public double getDiskCost()
```
    Gets the costs for disk.
    
    Returns:
    
    The disk cost, in bytes to be written and read.
  - setDiskCost
```
public void setDiskCost(double bytes)
```
    Sets the costs for disk for this Costs object.
    
    Parameters:
    
    bytes - The disk cost to set, in bytes to be written and read.
  - addDiskCost
```
public void addDiskCost(double bytes)
```
    Adds the costs for disk to the current disk costs for this Costs object.
    
    Parameters:
    
    bytes - The disk cost to add, in bytes to be written and read.
  - getCpuCost
```
public double getCpuCost()
```
    Gets the cost for the CPU.
    
    Returns:
    
    The CPU Cost.
  - setCpuCost
```
public void setCpuCost(double cost)
```
    Sets the cost for the CPU.
    
    Parameters:
    
    cost - The CPU Cost.
  - addCpuCost
```
public void addCpuCost(double cost)
```
    Adds the given CPU cost to the current CPU cost for this Costs object.
    
    Parameters:
    
    cost - The CPU cost to add.
  - getHeuristicNetworkCost
```
public double getHeuristicNetworkCost()
```
    Gets the heuristic network cost.
    
    Returns:
    
    The heuristic network cost, in bytes to be transferred.
  - setHeuristicNetworkCost
```
public void setHeuristicNetworkCost(double cost)
```
    Sets the heuristic network cost for this Costs object.
    
    Parameters:
    
    cost - The heuristic network cost to set, in bytes to be transferred.
  - addHeuristicNetworkCost
```
public void addHeuristicNetworkCost(double cost)
```
    Adds the heuristic costs for network to the current heuristic network costs for this Costs object.
    
    Parameters:
    
    cost - The heuristic network cost to add.
  - getHeuristicDiskCost
```
public double getHeuristicDiskCost()
```
    Gets the heuristic costs for disk.
    
    Returns:
    
    The heuristic disk cost.
  - setHeuristicDiskCost
```
public void setHeuristicDiskCost(double cost)
```
    Sets the heuristic costs for disk for this Costs object.
    
    Parameters:
    
    cost - The heuristic disk cost to set.
  - addHeuristicDiskCost
```
public void addHeuristicDiskCost(double cost)
```
    Adds the heuristic costs for disk to the current heuristic disk costs for this Costs object.
    
    Parameters:
    
    cost - The heuristic disk cost to add.
  - getHeuristicCpuCost
```
public double getHeuristicCpuCost()
```
    Gets the heuristic cost for the CPU.
    
    Returns:
    
    The heuristic CPU Cost.
  - setHeuristicCpuCost
```
public void setHeuristicCpuCost(double cost)
```
    Sets the heuristic cost for the CPU.
    
    Parameters:
    
    cost - The heuristic CPU Cost.
  - addHeuristicCpuCost
```
public void addHeuristicCpuCost(double cost)
```
    Adds the given heuristic CPU cost to the current heuristic CPU cost for this Costs object.
    
    Parameters:
    
    cost - The heuristic CPU cost to add.
  - addCosts
```
public void addCosts(Costs other)
```
    Adds the given costs to these costs. If for one of the different cost components (network, disk), the costs are unknown, the resulting costs will be unknown.
    
    Parameters:
    
    other - The costs to add.
  - subtractCosts
```
public void subtractCosts(Costs other)
```
    Subtracts the given costs from these costs. If the given costs are unknown, then these costs are remain unchanged.
    
    Parameters:
    
    other - The costs to subtract.
  - multiplyWith
```
public void multiplyWith(int factor)
```
  - divideBy
```
public void divideBy(int factor)
```
  - compareTo
```
public int compareTo(Costs o)
```
    The order of comparison is: network first, then disk, then CPU. The comparison here happens each time primarily after the heuristic costs, then after the quantifiable costs.
    
    Specified by:
    
    compareTo in interface Comparable<Costs>
    
    See Also:
    
    Comparable.compareTo(java.lang.Object)
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - equals
```
public boolean equals(Object obj)
```
    Overrides:
    
    equals in class Object
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - clone
```
public Costs clone()
```
    Overrides:
    
    clone in class Object

Back to Flink Website

Class Costs

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

UNKNOWN

Constructor Detail

Costs

Costs

Costs

Method Detail

getNetworkCost

setNetworkCost

addNetworkCost

getDiskCost

setDiskCost

addDiskCost

getCpuCost

setCpuCost

addCpuCost

getHeuristicNetworkCost

setHeuristicNetworkCost

addHeuristicNetworkCost

getHeuristicDiskCost

setHeuristicDiskCost

addHeuristicDiskCost

getHeuristicCpuCost

setHeuristicCpuCost

addHeuristicCpuCost

addCosts

subtractCosts

multiplyWith

divideBy

compareTo

hashCode

equals

toString

clone

Back to Flink Website