Hi, I'm struggling to understand some problems with respect to materialized views.
First, I want to understand the example mentioned in https://issues.apache.org/jira/browse/CASSANDRA-9928 explaining how multiple non-PK columns in the view PK can lead to unrepairable/orphanized entries. I understand that only happens if a node dies that pushed an "intermediate" state (the result of only one of several updates affecting the same entry) to it's view replica. The case mentioned looks like the following: initially all nodes have (p=1, a=1, b=1). Then two concurrent updates are send: a=2 and b=2. One node gets b=2, deletes view (a=1, b=1, p=1) and inserts (a=1, b=2, p=1), then dies. The others get a=1, when is why they delete (a=1, b=1, p=1) and insert (a=2, b=1, p=1). Then (a=1, b=2, p=1) will never be deleted. What I don't understand is, why that can never happen with a single column. Consider (p=1, a=1) with two updates a=2 and a=3. One node receives a=2, deletes view entry (a=1, p=1) and inserts (a=2, p=1), then dies. The others get a=3, delete (a=1, p=1) and insert (a=3, p=1). Now, how is (a=2, p=1) removed from the view replica that was connected to the dying node? I don't get what's different here. I would really appreciate if someone could share some insight here! Fridtjof
