I have some questions regarding backups for segments with NGA:
WinCC OA 3.20 (latest patch)
Redundant project
NGA with PostgreSQL
1. Backup Segments for ALERT group
The documentation states the following:
https://www.winccoa.com/documentation/W ... upSegments
The option "Backup Segments older than" for the ALERT group must be as large as possible or the automatic backup must not be configured for redundant projects. Backed up alert segments are set to read-only and each written alert needs updates of older alerts of the same DP. The updates are not possible when the alerts are in a read-only segment.
But in the chapter "Segment States" it states that backed up archives will be reopened as long as they are still online.
https://www.winccoa.com/documentation/W ... _segm.html
Online and Backed up: The segment exists locally and is available for read operations. It is automatically deleted if the parameters for deletion ("age") apply. If an additional value or an alert (correction values, alert update, etc.) is written to a segment that has already been backed up but is still online (status = online and backed up), the status of the segment changes to "online" and the old backup is replaced the next time a backup is triggered.
Is it save to enable backups for the ALERT groups, as long as I ensure that the retention period is high enough?
Example settings for ALERT group:
Retention Period: 2 Years
Segment Duration: 1 Week
Backup Segments older than: 1 Week
2. Correction values and Statistical Functions
If we enter a correction value on an segment in state "Online and Backed up" it should open this segment and allow to enter the correction value.
Is this correct?
If yes, does this also apply for the automatic recalculation of statistical functions (after a correction value has been entered) which are located in a different archive group (as long as these archives are also "Online and Backed up")?
Thank you in advance for your help.
BR
Dennis