com.bigdata.bop

Enum BOpEvaluationContext

java.lang.Object

java.lang.Enum<BOpEvaluationContext>

com.bigdata.bop.BOpEvaluationContext

All Implemented Interfaces:

Serializable, Comparable<BOpEvaluationContext>

public enum BOpEvaluationContext
extends Enum<BOpEvaluationContext>

Type safe enumeration indicates where an operator may be evaluated. Operators fall into several distinct categories based on whether or not their inputs need to be made available on specific nodes (HASHED or SHARDED), whether they can be evaluated anywhere their inputs may exist (ANY), or whether they must be evaluated at the query controller (CONTROLLER).

Note: All operators are evaluated locally when running against a standalone database.

Enum Constant Summary

Enum Constants

Enum Constant and Description
ANY The operator may be evaluated anywhere, including piecewise evaluation on any node of the cluster where its inputs are available.
CONTROLLER The operator must be evaluated on the query controller.
HASHED The input to the operator must be mapped across nodes using a hash partitioning schema and the operator must be evaluated on each hash partition.
SHARDED The input to the operator must be mapped across the shards on which the operator must read or write and the operator must be evaluated shard wise on the services having access to each shard.

Method Summary

Methods

Modifier and Type	Method and Description
static BOpEvaluationContext	valueOf(String name) Returns the enum constant of this type with the specified name.
static BOpEvaluationContext[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

ANY

public static final BOpEvaluationContext ANY

The operator may be evaluated anywhere, including piecewise evaluation on any node of the cluster where its inputs are available. This is used for operators which do not need to concentrate or coordinate their inputs such as ConditionalRoutingOp. It may also be used in combination with a remote access path to impose a DISTINCT filter across one or more shards or nodes.

See Also:

IPredicate.Annotations.REMOTE_ACCESS_PATH

HASHED

public static final BOpEvaluationContext HASHED

The input to the operator must be mapped across nodes using a hash partitioning schema and the operator must be evaluated on each hash partition. This is used for operators such as DistinctBindingSetOp.

SHARDED

public static final BOpEvaluationContext SHARDED

The input to the operator must be mapped across the shards on which the operator must read or write and the operator must be evaluated shard wise on the services having access to each shard. For example, PipelineJoin.

CONTROLLER

public static final BOpEvaluationContext CONTROLLER

The operator must be evaluated on the query controller. For example, SliceOp may not be evaluated piecewise.

Method Detail

values

public static BOpEvaluationContext[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (BOpEvaluationContext c : BOpEvaluationContext.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static BOpEvaluationContext valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null