Document entity state detection strategies.

Closes #1124

Author: mp911de

src/main/asciidoc/reference/mapping.adoc

@@ -518,6 +518,10 @@ CAUTION: Index creation on session initialization may have a severe performance
 
 include::./converters.adoc[]
 
+include::../{spring-data-commons-docs}/is-new-state-detection.adoc[leveloffset=+1]
+
+NOTE: Cassandra provides no means to generate identifiers upon inserting data. As consequence, entities must be associated with identifier values. Spring Data defaults to identifier inspection to determine whether an entity is new. If you want to use <<cassandra.auditing,auditing>> make sure to either use <<cassandra.template.optimistic-locking>> or implement `Persistable` for proper entity state detection.
+
 [[cassandra.mapping-usage.events]]
 == Lifecycle Events