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https://issues.apache.org/jira/browse/CASSANDRA-9198?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14497728#comment-14497728
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Benjamin Lerer commented on CASSANDRA-9198:
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Cassandra does not differentiate between an empty list and a list which is 
null. In Java deleting from an empty list is fine not from a list which is null.

Making the delete operation a noop operation can be done but from my opinion it 
is a breaking change so if we do it we should do it in 3.0.  

> Deleting from an empty list produces an error
> ---------------------------------------------
>
>                 Key: CASSANDRA-9198
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-9198
>             Project: Cassandra
>          Issue Type: Bug
>          Components: API
>            Reporter: Olivier Michallat
>            Assignee: Benjamin Lerer
>            Priority: Minor
>             Fix For: 3.0
>
>
> While deleting an element from a list that does not contain it is a no-op, 
> deleting it from an empty list causes an error.
> This edge case is a bit inconsistent, because it makes list deletion non 
> idempotent:
> {code}
> cqlsh:test> create table foo (k int primary key, v list<int>);
> cqlsh:test> insert into foo(k,v) values (1, [1,2]);
> cqlsh:test> update foo set v = v - [1] where k = 1;
> cqlsh:test> update foo set v = v - [1] where k = 1;
> cqlsh:test> update foo set v = v - [2] where k = 1;
> cqlsh:test> update foo set v = v - [2] where k = 1;
> InvalidRequest: code=2200 [Invalid query] message="Attempted to delete an 
> element from a list which is null"
> {code}
> With speculative retries coming to the drivers, idempotency becomes more 
> important because it determines which query we might retry or not. So it 
> would be better if deleting from an empty list succeeded.



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