CompilerHints (Flink : 2.0-SNAPSHOT API)

java.lang.Object
- org.apache.flink.api.common.operators.CompilerHints

```
@Internal
public class CompilerHints
extends Object
```
A class encapsulating compiler hints describing the behavior of the user function. If set, the optimizer will use them to estimate the sizes of the intermediate results. Note that these values are optional hints, the optimizer will always generate a valid plan without them as well. The hints may help, however, to improve the plan choice.

Constructor Summary

Constructors
Constructor Description

CompilerHints()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`addUniqueField(int field)`	Adds a field as having only unique values.
`void`	`addUniqueField(FieldSet uniqueFieldSet)`	Adds a FieldSet to be unique
`void`	`addUniqueFields(Set<FieldSet> uniqueFieldSets)`	Adds multiple FieldSets to be unique
`void`	`clearUniqueFields()`
`protected void`	`copyFrom(CompilerHints source)`
`float`	`getAvgOutputRecordSize()`
`float`	`getFilterFactor()`
`long`	`getOutputCardinality()`
`long`	`getOutputSize()`
`Set<FieldSet>`	`getUniqueFields()`	Gets the FieldSets that are unique
`void`	`setAvgOutputRecordSize(float avgOutputRecordSize)`
`void`	`setFilterFactor(float filterFactor)`
`void`	`setOutputCardinality(long outputCardinality)`
`void`	`setOutputSize(long outputSize)`

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

Constructor Detail
- CompilerHints
```
public CompilerHints()
```

Method Detail

getOutputSize
```
public long getOutputSize()
```

setOutputSize

public void setOutputSize(long outputSize)

getOutputCardinality
```
public long getOutputCardinality()
```

setOutputCardinality

public void setOutputCardinality(long outputCardinality)

getAvgOutputRecordSize
```
public float getAvgOutputRecordSize()
```

setAvgOutputRecordSize

public void setAvgOutputRecordSize(float avgOutputRecordSize)

getFilterFactor
```
public float getFilterFactor()
```

setFilterFactor

public void setFilterFactor(float filterFactor)

getUniqueFields
```
public Set<FieldSet> getUniqueFields()
```
Gets the FieldSets that are unique

Returns:

List of FieldSet that are unique

addUniqueField
```
public void addUniqueField(FieldSet uniqueFieldSet)
```
Adds a FieldSet to be unique

Parameters:

uniqueFieldSet - The unique FieldSet

addUniqueField
```
public void addUniqueField(int field)
```
Adds a field as having only unique values.

Parameters:

field - The field with unique values.

addUniqueFields
```
public void addUniqueFields(Set<FieldSet> uniqueFieldSets)
```
Adds multiple FieldSets to be unique

Parameters:

uniqueFieldSets - A set of unique FieldSet

clearUniqueFields
```
public void clearUniqueFields()
```

copyFrom

protected void copyFrom(CompilerHints source)