12c SOA - DVM VS XREF

Introduction:
When an object flows from one system to another system, both using their own entities to represent the same type of object, transformation is required to map the entity from one system to another.

For example, when a new customer is created in a SAP application, you might want to create a new entry for the same customer in your Oracle E-Business Suite application named as EBS.

So the required functionality is that these two entities should be mapped from different domains. Even if in future, another domain gets added, again this is the requirement to represent that entity in some common entity format.
Oracle SOA offers two solutions:

1. Domain-Value Maps (DVM)
2. Cross References (XREFs)

Domain-Value Maps (DVMs):

• Domain-Value Maps enable mapping of vocabulary in one domain to another, which is useful when different domains represent the same data in different ways.

• The limitation is that DVM is a static XML file where all the mappings are already defined in design time.
• DVM is best when it has small set of mapping values. When it is small set of values, you can directly map values between multiple domains. A direct mapping of values between two or more domains is also known as Point-to-Point mapping. Internal cache manager increases the performance tremendously in this case, as xml document always resides in runtime memory.

Click here how-to-create-dvm to get more details on DVM implementation steps.

Cross References (XREFs):

• Using cross references, you can dynamically populate, maintain, and map values for equivalent entities created by different applications.
• It is dynamic in nature since the values to the XREF can be populated dynamically.
• It is stored in XREF_DATA table in the SOA_INFRA schema in SOA Dehydration store referenced by the jdbc/xref JNDI name.  
• When creating, updating, and deleting objects in one application, there may be a need to propagate the changes to other applications. For example, when a new customer is created in a SAP application, you may need to create a new entry for the same customer in your Oracle E-Business Suite application (EBS). However, since the applications being integrated are using different entities and IDs to represent the same information you need to cross reference these entities.
• As the cross reference data is persisted in a database, it remains available for applications until explicitly deleted, preferably by using the appropriate XREF functions.

Click here how-to-create-Cross-reference to get more details on XREF implementation steps.