com.bigdata.rdf.changesets

Enum ChangeAction

java.lang.Object

java.lang.Enum<ChangeAction>

com.bigdata.rdf.changesets.ChangeAction

All Implemented Interfaces:

Serializable, Comparable<ChangeAction>

public enum ChangeAction
extends Enum<ChangeAction>

Attempting to add or remove statements can have a number of different effects. This enum captures the different actions that can take place as a result of trying to add or remove a statement from the database.

Enum Constant Summary

Enum Constants

Enum Constant and Description
INSERTED The focus statement was not in the database before and will be in the database after the commit.
REMOVED The focus statement was in the database before and will not be in the database after the commit.
UPDATED This change action can only occur when inference and truth maintenance are enabled on the database.

Method Summary

Methods

Modifier and Type	Method and Description
static ChangeAction	valueOf(String name) Returns the enum constant of this type with the specified name.
static ChangeAction[]	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

INSERTED

public static final ChangeAction INSERTED

The focus statement was not in the database before and will be in the database after the commit. This can be the result of either explicit addStatement() operations on the SAIL connection, or from new inferences being generated via truth maintenance when the database has inference enabled. If the focus statement has a statement type of explicit then it was added via an addStatement() operation. If the focus statement has a statement type of inferred then it was added via truth maintenance.

REMOVED

public static final ChangeAction REMOVED

The focus statement was in the database before and will not be in the database after the commit. When the database has inference and truth maintenance enabled, the statement that is the focus of this change record was either an explicit statement that was the subject of a removeStatements() operation on the connection, or it was an inferred statement that was removed as a result of truth maintenance. Either way, the statement is no longer provable as an inference using other statements still in the database after the commit. If it were still provable, the explicit statement would have had its type changed to inferred, and the inferred statement would have remained untouched by truth maintenance. If an inferred statement was the subject of a removeStatement() operation on the connection it would have resulted in a no-op, since inferences can only be removed via truth maintenance.

UPDATED

public static final ChangeAction UPDATED

This change action can only occur when inference and truth maintenance are enabled on the database. Sometimes an attempt at statement addition or removal via an addStatement() or removeStatements() operation on the connection will result in a type change rather than an actual assertion or deletion. When in inference mode, statements can have one of three statement types: explicit, inferred, or axiom (see StatementEnum). There are several reasons why a statement will change type rather than be asserted or deleted:

• A statement is asserted, but already exists in the database as an inference or an axiom. The existing statement will have its type changed from inference or axiom to explicit.
• An explicit statement is retracted, but is still provable by other means. It will have its type changed from explicit to inference.
• An explicit statement is retracted, but is one of the axioms needed for inference. It will have its type changed from explicit to axiom.

Method Detail

values

public static ChangeAction[] 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 (ChangeAction c : ChangeAction.values())
    System.out.println(c);

Returns:

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

valueOf

public static ChangeAction 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