Upgrading existing Rdbms databases to support Unicode and UTC

By default, from NiagaraAX-3.8, all Rdbms databases have a property called Use Unicode Encoding Scheme. The value of this property defaults to false to support existing Rdbms databases. If you want the full UTF-8 Unicode support (NVARCHAR columns instead of VARCHAR columns), set this property to true before you connect to your database for the first time. In addition, from NiagaraAX-3.8, most Rdbms databases have a property called Timestamp Storage allowing the export or update of history timestamps to Coordinated Universal Time (UTC). The value of this property defaults to Dialect Default to maintain backwards compatibility with the existing history export mechanism.

This section describes how to upgrade one or more existing Rdbms databases to support Unicode and/or UTC. An Update Wizard is available to help you easily perform each upgrade using the following steps:

NOTE: The upgrade of Rdbms Database’s to support either Unicode or UTC using the Update Wizard is described in separate procedures below although both upgrades may be carried out in the same wizard session.

Upgrading existing Rdbms databases to support Unicode

Right-click on the RdbmsNetwork in the nav tree and select Update Wizard. The Database Update Wizard dialog displays.
Select Update text column encodings to UTF-8 (Unicode) in the Update Procedures dialog. Click the Next button at the bottom of the dialog.
Select one or more databases to update to UTF-8 (Unicode). Click the Next button at the bottom of the dialog.
The wizard completes and displays its results for review.

Upgrading existing Rdbms databases to support UTC

Right-click on the RdbmsNetwork in the nav tree and select Update Wizard. The Database Update Wizard dialog displays.
Select Update timestamp columns to UTC (Coordinated Universal Time) in the Update Procedures dialog. Click the Next button at the bottom of the dialog.
Select one or more databases to update to UTC. Click the Next button at the bottom of the dialog.
Specify the current policy being used to store database timestamps by selecting either the Timestamps are being stored using the station timezone or Timestamps are being stored using the history config timezone options. Click the Next button at the bottom of the dialog.
The wizard completes and displays its results for review.

When the procedures and databases have been specified in the Update Wizard, the updates are submitted as jobs to the Job Service. The Update Wizard will process the database tables and change the data types of string valued columns to the NVARCHAR data type and will adjust the database timestamps to UTC time. Visibility on the progress of individual jobs is provided within the wizard itself and can be viewed from the Job Service at a later stage as well. The update operations are atomic. This implies they either complete entirely or will be rolled back entirely if any error occurs.

CAUTION: The Unicode and UTC upgrade procedures are one-way only and cannot be reversed. It is highly recommended that you back up the database prior to running the upgrades.

NOTE: If either or both upgrade procedures (Unicode and UTC) are run, the wizard automatically sets both the Use Unicode Encoding Scheme and Timestamp Storage properties on the database device property sheet to true and Utc Timestamp respectively. The Timestamp Storage property will also become read-only and can only be made writable again by right clicking on the database device and selecting Actions Allow Dialect Modifications.