Archive to Group Mapping

The NGA Group assignment panel is opened. You can select the default groups or create new groups. If you want to create a new group, click on the Plus button on the right - see figure below. You can select how to map the value archives to NGA groups freely. The Default mapping is "one-to-one" (e.g. 5 minutes to 5 minutes).

Figure 1. NGA Group Assignment
Figure 2. Predefined Groups

Create new group

Figure 3. Create new group

The Group Name in DB specifies the name of the group in the database. The group name again is the name shown in NGA. You can change these names. Select the backend type from the drop-down menu. You can add InfluxDB® (managed), InfluxDB® (unmanaged), PostgreSQL® (managed), PostgreSQL® (unmanaged) . For the managed databases WinCC OA creates and starts/stops the database. For the unmanaged databases, the database must be available and the connection settings of this backend must be configured later by using the Basic Configuration of the Database Engineering . You can also change the Storage Settings. For the Storage Settings, see chapter Storage Settings.

Figure 4. Storage Settings
Under Settings for managed PostgreSQL® database the settings for the PostgreSQL® database are specified. Enter a database user, the password and the PostgreSQL® port number. The default port number is 15432. The settings are used for the PostgreSQL® database managed by WinCC OA.
Figure 5. Settings for managed PostgreSQL® database
Important: Imported values/alarms that are outside the retention period of their target NGA archive group cannot be written to the segments that correspond to their source time and are discarded. Segments that are outside the retention period are not created. They may even have already been deleted or backed up and can therefore no longer be written to. When importing data into NGA, the retention period of the NGA archive groups must be configured according to the time range to be imported.
Important:

If you have large retention periods in archive groups in order to import several years of historical data from HDB/RAIMA into PostgreSQL®, it is advisable to set the database-specific setting backend.suppressViewGeneration of the PostgreSQL® backend to true. This may be necessary in order to import data successfully and avoid overloading the database.

If the error message:
WCCOAnextgenarch(118), 2023.11.27 15:13:49.740, IMPL, SEVERE, 69, Database error, ERROR: out of shared memory
is displayed when restarting a project, it is recommended to set max_locks_per_transaction in <PG data path>/postgresql.conf to a higher value and restart the PostgreSQL® database to apply the new setting.