OpenAccess 2.2 Feature List

OpenAccess can add new kinds of data to the data model as newer versions are released. For example, OpenAccess added a new feature to allow figures to be grouped and manipulated as a single entity.

Each new kind of data added to the data model is called a feature. When a database contains one or more instances of the new kind of data, then it is using that feature. In many cases, older applications will not be able to use databases that have new features.

OpenAccess includes the infrastructure to support feature-based compatibility, which means that OpenAccess has the ability to control the access that an application has to an OpenAccess database based on

The version of OpenAccess on which the application was compiled
The new features used in that database

When OpenAccess releases a new feature, that feature has a set of policies that define how applications can access databases that include those new features.

For more information, refer to Feature-Based Data Compatibility in Compatibility for OpenAccess Applications and Data.

Feature List

The following table lists the new features available in the OpenAccess 2.2 releases and shows their policies. The table also shows the part of the OpenAccess data model that contains the new feature, and specifies the data model revision that first contains the new feature.

The range for a policy specifies the OpenAccess versions against which the policy applies. For example, in the table, the Cannot open policy for the Huge Database feature is applicable to an application using any release prior to OpenAccess 2.2.4. Applications using 2.2.4 or later can open the database.

Feature Name	Policy	Range	Data Model
Huge Database	Cannot open	`ver < 2.2.4`	oacBaseDBType oacNoDomain oacFutureCategory oacUnknonwType oacAdditionDataModelModType

Policy Definitions

Cannot open

The database contains a new feature and cannot be opened.
The version of OpenAccess software that you are using was released before 2.2 p029 and does not include the infrastructure to support feature-based compatibility. The database containing the new feature cannot be opened, and the exception message will not contain details about the feature or the compatibility error.
Cannot open with compatibility exception

The database contains a new feature and cannot be opened.
The version of OpenAccess software that you are using is older than the version of OpenAccess that created the database containing the new feature. The database containing the new feature cannot be opened, but the exception does provide an oaCompatibilityError with details about the compatibility error.
Cannot append

The database contains a new feature and cannot be opened for append 'a' mode.
The version of OpenAccess software that you are using is older than the version of OpenAccess that created the database containing the new feature. The database cannot be opened in append mode 'a', but can be opened in read mode or in a forced append mode ‘A’. If the database is opened in one of these modes and saved, the data for the new feature will be lost.

Feature Information

Huge Database

OpenAccess provides the ability to open very large database in which a single type of data takes over 4 Gbytes of memory.

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