com.aliyun.odps.table.optimizer.predicate

Class Predicate

java.lang.Object

com.aliyun.odps.table.optimizer.predicate.Predicate

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

Attribute, BinaryPredicate, CompoundPredicate, Constant, InPredicate, RawPredicate, UnaryPredicate

public abstract class Predicate
extends Object
implements Serializable

开放存储支持谓词下推所使用的谓词

谓词下推并不意味着扫描数据量一定会减少，而是通过谓词尽可能的过滤数据桶 只能保证扫描数据中一定包含满足谓词的桶

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Predicate.PredicateType 定义谓词的类型

Field Summary

Fields

Modifier and Type	Field and Description
static Predicate	NO_PREDICATE

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object o)
Predicate.PredicateType	getType()
int	hashCode()
abstract String	toString() 要求所有子类实现toString方法，以便输出谓词的字符串表示

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Field Detail

NO_PREDICATE

public static final Predicate NO_PREDICATE

Method Detail

getType

public Predicate.PredicateType getType()

toString

public abstract String toString()

要求所有子类实现toString方法，以便输出谓词的字符串表示

Overrides:

toString in class Object

Returns:

传给服务端的谓词

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object