DATAJDBC-400 - Deprecated Identifier for those events that also have an entity.

Retrieval of the Identifier has been shown to cost significant performance.

Original pull request: #164.

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/event/RelationalEventWithId.java

@@ -39,11 +39,13 @@ public class RelationalEventWithId extends SimpleRelationalEvent implements With
 		this.id = id;
 	}
 
-	/*
+	/**
-	 * (non-Javadoc)
+	 * Events with an identifier will always return a {@link Specified} one.
-	 * @see org.springframework.data.jdbc.core.mapping.event.JdbcEvent#getId()
+	 *
+	 * @deprecated obtain the id from the entity instead.
 	 */
 	@Override
+	@Deprecated
 	public Specified getId() {
 		return id;
 	}

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/event/SimpleRelationalEvent.java

@@ -43,11 +43,11 @@ class SimpleRelationalEvent extends ApplicationEvent implements RelationalEvent
 		this.change = change;
 	}
 
-	/*
+	/**
-	 * (non-Javadoc)
+	 * @deprecated obtain the id from the entity instead.
-	 * @see org.springframework.data.jdbc.core.mapping.event.JdbcEvent#getId()
 	 */
 	@Override
+	@Deprecated
 	public Identifier getId() {
 		return (Identifier) getSource();
 	}