Using Data Stores
A data store provides a mechanism to update or consult data that will persist beyond the scope of the current process. It enables storage of input message flows, and their retransmission via one or several output message flows.Introduction to the data store concept
Depending on the context being described, you can use the RE or RDB data stores.
A Relationship Entity data store describes a database in the form of entities or classes.Relational Database data store represents a data store in the form of tables or table views.A data store references an data domain.
A physical RDB domain is held by a database. An RDB information storage structure is held by a package.If you describe an application system, only physical data stores can be used.
A physical data store represents the implementation of a logical data store.For more details, see Describing physical data stores.If you describe a logical application system, only physical data stores can be used.
A logical data store represents the use of data via application systems without considering how their access will be concretely implemented.For more details, see Describing a logical data store.Last but not least, you can also distinguish data stores local to a system from external data stores that are positioned on the border of diagrams.
A local data store represents a data store used only inside the system described.An external data store represents a data store used inside and outside of the system described.Usage contexts
Data stores can be described in the following diagrams:
• application system structure diagrams,
• application structure diagrams,
• Logical application system structure diagrams
Describing physical data stores
A physical data store represents the implementation of a logical data store.You can use only the following data stores in an application system structure diagram as well as in an application structure diagram:
• Local or external
• RE (Relationship Entity) or RDB (Relational Database).
A Relationship Entity data store describes a database in the form of entities or classes.Relational Database data store represents a data store in the form of tables or table views.Creating a local RDB physical data store
A local data store represents a data store used only inside the system described.To create, for example, a local RDB physical data store based on an application system structure diagram:
1. Open the diagram that interests you.
2. In the application system structure diagram insert toolbar, click Local Physical Data Store.
3. Click in the frame of the described application system.
A creation dialog box prompts you to select ER Physical Data Area. This is the RDB physical structure that will concretely support the database.
4. Select an existing physical domain, or create a new application system.
5. Click OK.
The local RDB physical data store appears in the diagram with the name of the physical domain.
A physical RDB domain is held by a database.Creating an external RE physical data store
An external data store represents a data store used inside and outside of the system described.To create, for example, an external RE physical data store based on an application system structure diagram:
1. Open the diagram that interests you.
2. In the application system structure diagram insert toolbar, click External ER Physical Data Store.
3. Click in the frame of the described application system.
A creation dialog box prompts you to select ER Physical Data Area. This is the RE physical structure that will concretely support the database.
4. Select an existing RE physical data domain, or create a new application system.
5. Click OK.
The external RE physical data store appears on the border of the diagram with the name of the external RE physical data domain.
A physical RE domain is held by a package.Describing access to a physical data store
The following components can have read and right access to a physical data store:
• Application system type elements represent the two application systems used.
An application system is an assembly of other application systems, applications and end users interacting with application components to implement one or several functionalities.• The Application components represent the applications used.
An application is a software component that can be deployed and provides users with a set of functionalities.• The platform application components.
A platform application component represents the fact that the technology used plays a role of platform in the described application. For example, Tomcat is a platform component for SageCRM.To create a read access to the data store:
1. In the diagram insert toolbar, click Link.
2. Draw a link between the data store and the entity that reads the data (component or application system use).
A Read-only access to data storage is automatically created with the link from the data store to the entity.
To create a link with write access, you must draw a link between this entity and the data store to which it has write access. A Write access to data storage is then automatically created.Describing a logical data store
A logical data store represents the use of data via application systems without considering how their access will be concretely implemented.In a logical application system structure diagram, you can use only the local or external RE data stores.
A logical application system is an assembly of other application architectures, logical applications and end users, interacting with application components to implement one or several functions.A logical application is a set of application functionalities that is independent of a particular implementation. For example, the classification of all purchase request processing applications implemented in an enterprise.Creating a local logical data store
A logical data store represents the use of data via application systems without considering how their access will be concretely implemented.To create, for example, a local logical data store based on a logical application system structure diagram:
1. Open the diagram that interests you.
2. In the application system structure diagram insert toolbar, click Local Logical Data Store.
3. Click in the frame of the described logical application system.
A creation dialog box prompts you to select the RE Data Logical Store Structure. This is the RE physical structure that will concretely support the database.
4. Select an existing RE logical data domain, or create a new application system.
5. Click OK.
The local logical data store appears in the diagram with the name of the RE logical data domain.
An RE logical data store structure is held by a package.Describing access to a logical data store
The following components can access a logical data store with read and write access:
• the logical application systems
A logical application system is an assembly of other application architectures, logical applications and end users, interacting with application components to implement one or several functions.• The logical application components that represent the logical applications used in the context of the described logical application system.
A logical application component describes the role of a logical application in a composition relationship with a parent logical application or a logical application system.To create read access to the logical data store:
1. In the diagram insert toolbar, click Link.
2. Draw a link between the data store and the entity that reads the data (logical application component or logical application system use).
A Read-only access to data storage is automatically created with the link from the data store to the entity.
To create a link with write access, you must draw a link between this entity and the data store to which it has write access. A Write access to data storage is then automatically created.