Working with Integration Interfaces

 Components of an Integration Interface

An integration interface is made up of and defined by the following components:

• Target Datastore
  The target datastore is the element that will be loaded by the interface. This datastore may be permanent (defined in a model) or temporary (created by the interface).
  
• Datasets
  One target is loaded with data coming from several datasets. Set-based operators (Union, Intersect, etc) are used to merge the different datasets into the target datastore.
  Each Dataset corresponds to one diagram of source datastores and the mappings used to load the target datastore from these source datastores.
  
• Diagram of Source Datastores
  A diagram of sources is made of source datastores - possibly filtered - related using joins. The source diagram also includes lookups to fetch additional information for loading the target.
  Two types of objects can be used as a source of an interface: datastores from the models and interfaces. If an interface is used, its target datastore -temporary or not- will be taken as a source.
  The source datastores of an interface can be filtered during the loading process, and must be put in relation through joins. Joins and filters are either copied from the models or can be defined for the interface. Join and filters are implemented in the form of SQL expressions.
  
• Mapping
  A mapping defines the transformations performed on one or several source columns to load one target column. These transformations are implemented in the form of SQL expressions. Each target column has one mapping per dataset. If a mapping is executed on the target, the same mapping applies for all datasets.
  
• Staging Area
  The staging area is a logical schema into which some of the transformations (joins, filters and mappings) take place. It is by default the same schema as the target's logical schema.
  It is possible to locate the staging area on a different location (including one of the sources). It is the case if the target's logical schema is not suitable for this role. For example, if the target is a file datastore, as the file technology has no transformation capability.
  Mappings can be executed either on the source, target or staging area. Filters and joins can be executed either on the source or staging area.
  
• Flow
  The flow describes how the data flows between the sources, the staging area if it is different from the target, and the target as well as where joins and filters take place. The flow also includes the loading and integration methods used by this interface. These are selected by choosing Loading and Integration Knowledge Modules (LKM, IKM).
  
• Control
  An interface implements two points of control. Flow control checks the flow of data before it is integrated into the target, Post-Integration control performs a static check on the target table at the end of the interface. The check strategy for Flow and Post-Integration Control is defined by a Check Knowledge Module (CKM).
  

The interfaces use the following components that should be created before the interface:

• Datastores that will be used as sources and target of the loading process must be populated into the data models.
  
• The correct physical and logical schemas along with their mapping in the interface's execution context must be defined prior to creating the interface, if the staging area is to be defined in a schema different than any of the sources or the target.
  
• Knowledge Modules (IKM, LKM, CKM) that will be selected in the flow must be imported into the project.
  
• Variables, Sequence and User Functions that will be used in the mapping, filter or join expressions must be created in the project.
  

11.2 Introduction to the Interface Editor

The interface Editor provides a single environment for designing integration interfaces. The interface Editor enables you to create and edit integration interfaces.

Figure 11-1 Interface Editor