Mandatory/Optional Upgrade

The upgrade process enters an upgrade number in databases, indicating the level to which they have been upgraded. This will make it easy to detect, on opening, whether a database has or has not been upgraded. There are two variants of upgrades, mandatory or optional. An upgrade number represents either a mandatory upgrade or an optional upgrade.

Mandatory upgrade means that the database requires an upgrade for software being able to write to the database.

Optional upgrade means that the software manages to write to the database even though not upgraded. This means that new software versions provided with an optional upgrade facilitates a graceful deployment and installation as such a version very well can operate in a mixed environment with previous software versions. However, new software does not share the benefits the Parts Upgrade provides until the optional upgrade is applied. A soon as applied, the database is no longer accessible from previous software versions.

Note:
A gradual upgrade, database per database also enables for a graceful upgrade process, not all databases in a project need to be upgraded at once.