JDO Mapping Guide (v5.2) Table of Contents Classes . 3 Persistence Capable Classes. 3 Persistence-Aware Classes . 4 Read-Only Classes. 4 Detachable Classes . 5 SoftDelete . 5 Inheritance. 7 Discriminator . 8 New Table . 9 Subclass table . 11 Superclass table . 12 Complete table . 15 Retrieval of inherited objects . 16 Identity . 18 Nondurable Identity . 18 Datastore Identity . 19 Application Identity. 21 Compound Identity Relationships . 28 Versioning . 40 Versioning using a surrogate column . 40 Versioning using a field/property of the class. 40 Auditing . 42 Defining the Current User . 43 Full Traceability Auditing . 43 Fields/Properties. 45 Persistent Fields . 45 Persistent Properties . 45 Overriding Superclass Field/Property MetaData . 46 Making a field/property non-persistent . 47 Making a field/property read-only. 47 Field Types . 49 Primitive and java.lang Types. 50 java.math types . 51 Temporal Types (java.util, java.sql, java.time, Jodatime). 51 Collection/Map types . 53 Enums . 55 Geospatial Types . 56 Other Types . 62 Arrays . 63 Generic Type Variables. 64 JDO Attribute Converters . 65 Types extending Collection/Map . 67 TypeConverters (DataNucleus Internals). 69 Column Adapters . 69 RDBMS Override of mapping . 70 Value Generation . 71 native . 72 sequence. 72 identity . 73 increment. ..