com.bigdata.bop.controller

Interface SubqueryOp.Annotations

All Superinterfaces:

BOp.Annotations, BufferAnnotations, JoinAnnotations, PipelineOp.Annotations, SubqueryAnnotations, SubqueryJoinAnnotations

Enclosing class:

SubqueryOp

public static interface SubqueryOp.Annotations
extends SubqueryJoinAnnotations

Field Summary

Fields

Modifier and Type	Field and Description
static String	ASK_VAR When non-null, the IVariable which will be bound to true iff there is at least one solution for the subquery.
static boolean	DEFAULT_IS_AGGREGATE
static String	IS_AGGREGATE Boolean annotation should be true if the subquery is an aggregate (default false).
static String	SELECT The IVariable[] projected by the subquery (optional).

Fields inherited from interface com.bigdata.bop.join.JoinAnnotations

CONSTRAINTS, DEFAULT_LIMIT, JOIN_TYPE, LIMIT

Fields inherited from interface com.bigdata.bop.PipelineOp.Annotations

ALT_SINK_REF, DEFAULT_LAST_PASS, DEFAULT_MAX_MEMORY, DEFAULT_MAX_MESSAGES_PER_TASK, DEFAULT_MAX_PARALLEL, DEFAULT_PIPELINE_QUEUE_CAPACITY, DEFAULT_PIPELINED, DEFAULT_REORDER_SOLUTIONS, DEFAULT_SHARED_STATE, LAST_PASS, MAX_MEMORY, MAX_MESSAGES_PER_TASK, MAX_PARALLEL, PIPELINE_QUEUE_CAPACITY, PIPELINED, REORDER_SOLUTIONS, SHARED_STATE, SINK_REF

Fields inherited from interface com.bigdata.bop.BOp.Annotations

BOP_ID, CONTROLLER, DEFAULT_CONTROLLER, DEFAULT_EVALUATION_CONTEXT, DEFAULT_TIMEOUT, EVALUATION_CONTEXT, NAMESPACE, TIMEOUT

Fields inherited from interface com.bigdata.bop.BufferAnnotations

CHUNK_CAPACITY, CHUNK_OF_CHUNKS_CAPACITY, CHUNK_TIMEOUT, chunkTimeoutUnit, DEFAULT_CHUNK_CAPACITY, DEFAULT_CHUNK_OF_CHUNKS_CAPACITY, DEFAULT_CHUNK_TIMEOUT

Fields inherited from interface com.bigdata.bop.controller.SubqueryAnnotations

SUBQUERY

Field Detail

ASK_VAR

static final String ASK_VAR

When non-null, the IVariable which will be bound to true iff there is at least one solution for the subquery. When specified, SELECT SHOULD be null in order to project all bindings from the parent's context into the subquery. However, bindings in the subquery WILL NOT be projected back into the parent.

Note: This supports EXISTS and NOT EXISTS semantics.

SELECT

static final String SELECT

The IVariable[] projected by the subquery (optional).

Rule: A variable within a subquery is distinct from the same name variable outside of the subquery unless the variable is projected from the subquery.

When this option is given, only the variables projected by the subquery will be visible during the subquery (this models SPARQL 1.1 subquery variable scope semantics). A variable having the same name in the parent context and the subquery which is not projected by the subquery is a distinct variable. This constraint is enforced by passing only the projected variables into the subquery and then merging the unprojected variables from the source solution into each result produced by the subquery for a given source solution.

When this option is not given, all variables are passed into the subquery (basically, the semantics are those of SELECT * ).

Note: This overrides the semantics of the same named annotation on the JoinAnnotations interface.

IS_AGGREGATE

static final String IS_AGGREGATE

Boolean annotation should be true if the subquery is an aggregate (default false).

Note: We need to have distinct IAggregate objects in each subquery issued since they have internal state in order to prevent inappropriate sharing of state across invocations of the subquery.

DEFAULT_IS_AGGREGATE

static final boolean DEFAULT_IS_AGGREGATE

See Also:

Constant Field Values