Partition in AX 2012

The business data in each partition is isolated from the data in all other partitions in the same installation of Microsoft Dynamics AX. Business data that is shared among companies is shared only among companies that are in the same partition.

Each Microsoft Dynamics AX client session starts in a partition. The session cannot later be switched to another partition. Instead the user must start a new session and direct it to start in a different partition, if the user is authorized for another partition. The system prevents even the system administrator from accessing data in any partition other than the current partition of the session.

Overview of Partitions and Legal Entities

• Definition of a partition is: A division of an application’s processing into logical or functional parts. 
• The purpose of a partition is to logically separate the data within its boundaries from the data in other partitions. A partition enables the AOS to isolate the data in the partition from users who are not authorized to access the data. 
• For example, a holding corporation might have several subsidiaries or other legal entities. An installation of Microsoft Dynamics AX for the corporation can have several partitions, perhaps one for each subsidiary.
• Each partition contains at least one company or legal entity. A legal entity occurs in only one partition.
• When you create a legal entity, the system assigns it to the current partition. The legal entity can never be moved to another partition.
• However, its data can be exported from the partition and then imported to another company in another partition.
• To achieve this separation, Microsoft Dynamics AX adds a column to each table that contains data that must be isolated.
• This column contains a partition ID, which is the RecId of an entry in the Partitions table.
  In a partitioned table, rows that contain the same partition ID value belong to the same partition.
• The partition ID is also added to relevant indexes.

1. AX Query - Select * From CustTable
2. SQL (Before Partition) - Select * from custTable where dataareaid = ‘Dat’
3. SQL (After data partiion) - Select * from custTable where data areaid = ‘Dat’ and Partion key = ‘Initial’
4. No cross company query on partitions are allowed like the cross company query
5. You can know the current partition through ‘getcurrentpartitionrecid()’ similar to ‘curext()’
6. Batch servers work across partitions
7. AIF works across partitions

• Partitions are defined in the Partitions form, where the system administrator creates the partition and provides a partition key.
• A partition key identifies a partition by using a unique string value that the system administrator specifies.
• Microsoft Dynamics AX displays the partition key in the title bar of the client application. Partitions can also be defined during installation and upgrade.

Data partitioning architecture



Scope of Data Isolation

• It is important to understand that data partitions do not create separate installations of Microsoft Dynamics AX. Consider the following characteristics of partitioned systems:
• Shared AOS - A partitioned system is created in the context of a single instance of Microsoft Dynamics AX Application Object Server (AOS) or an AOS cluster. When Microsoft Dynamics AX is first set up, the system creates a default partition. The partition key for the default partition is "initial". Additional partitions can be created during installation or upgrade, or at any time after the system is deployed. After a partition has been created, it cannot be deleted.
• Shared database - In a partitioned system, all data is stored in the same database or database cluster. Partitions provide only logical data separation. No physical isolation of data occurs. Many system tables are shared tables that do not contain a column for the partition ID.
• Shared AOT - A partitioned system has one Microsoft Dynamics AX Application Object Tree (AOT). Customizations are always shared across all partitions. The model store database is not partitioned. Metadata that describes objects in the AOT is shared. Custom code is shared across the system.
• By default, code runs in the context of the partition for the current session. This behavior resembles the behavior of X++, which handles companies by using the dataAreaId field. Therefore, pre-existing code that uses the X++ query mechanism works without modification. Direct SQL calls must be modified to filter on the context of the current partition.
• For more information about using data partitions in development projects, see Partitions, Companies, and Data Isolation in Microsoft Dynamics AX.
• The Microsoft Dynamics AX cross-reference system is shared. Role definitions are shared across the system. In Microsoft Dynamics AX 2012 R2 and later versions, multi-partition configurations have no new requirements to define or maintain reports.
• Common administration - Users who have the system administrator role can access data in all partitions. However, to view data in a particular partition, the administrator must log on to a client instance for that partition. System administrators can create new partitions. Both system administrators and security administrators can manage users in the context of a partition. License keys and configuration keys are shared across the system.
• Common application integration - In a partitioned system, Services and Application Integration Framework (AIF) is a shared subsystem. To guarantee that incoming requests are correctly isolated, you can restrict an inbound integration port to a particular partition. Additionally, you can specify a target partition for an incoming request by including the partition key in an XML element in the header of the document. Similarly, outbound responses indicate the source partition for the response data by including the partition key in the header. Because AIF uses a single gateway queue, a system administrator can view all documents in the queue, AIF history, or exceptions list in any partition. The forms that display these lists now have a field that shows the partition key for each document.
• Common batch framework - Like AIF, the batch processing framework is a shared subsystem. One batch server is shared across partitions. However, each batch job is associated with a specific partition. The batch server executes batch jobs in the context of the correct partition. To view batch jobs or their history, you must log on to the partition that the batch jobs are associated with.
• Separate application data - Access to application data is controlled by a combination of the partition ID and the user's role and permissions. The Microsoft Dynamics AX client does not let users view unified data across partitions. Microsoft Dynamics AX does not provide a query mechanism to retrieve and combine data from multiple partitions.
• Separate organizational hierarchies - Each partition contains its own organizational hierarchy, which includes one or more legal entities. Like a new deployment of Microsoft Dynamics AX, each partition that is created contains the DAT company as a default legal entity. System administrators can add legal entities to each partition. Legal entities are never shared between partitions, even if the legal entities have the same name.
• Separate user configurations - Each partition contains its own list of authorized users. The system administrator who created the partition is automatically created as a user who has the system administrator role in the new partition. After a system administrator logs on to a partition, he or she can add authorized users to the partition. A user can be authorized to access data in more than one partition. However, the user must be created and managed separately in each partition. This user must use a separate client configuration to start a separate client session for each partition. Each user is associated with a default partition. This default partition can be changed by a system administrator. A user who logs on to Microsoft Dynamics AX by using a default client configuration is logged on to the user's default partition. The Microsoft Dynamics AX client application displays the partition key for the current session in the title bar of the main window. User roles are assigned for each partition.