What is the difference between %ID and ID in a database table? Both seem to reference the same column labelled ID.
For context, I am trying to create a viewer class for an existing persistent class.
Let us call the persistent class A, with SqlTableName = OldA.
The viewer class will be B with SqlTableName = A and ViewQuery = {select %ID, <other fields> from <some other class with the same fields as A>}
In A, there exists a class query: select %ID from A. However, A fails to compile, giving an error: "Field '%ID' not found in applicable tables". If the %ID is replaced with ID, the class compiles.

I was understanding the cluster configuration supported by the Cache. Have couple of queries around that:
1. In Cache version 2018.2, there is a shrading concept which splits the data of a Master Data server into multiple small data server which store shraded data.
How do we protect (backup and restore) such environment, should we also backup/restore the multiple small data servers along with Master data server. Any documentation around this will really help.
2.