[CASSANDRA-13130] Strange result of several list updates in a single request

• Type: Bug
• Status: Resolved
• Priority: Low
• Resolution: Fixed
• Fix Version/s: 2.2.10, 3.0.13, 3.11.0, 4.0-alpha1, 4.0
• Severity: Low
• Assignee: Benjamin Lerer
• Reporter: Mikhail Krupitskiy

Authors

Benjamin Lerer

Reviewers

Sylvain Lebresne

• Created: 17/Jan/17 17:41
• Updated: 15/May/20 08:02
• Resolved: 10/Mar/17 20:45

Description

Let's assume that we have a row with the 'listColumn' column and value {1,2,3,4}.
For me it looks logical to expect that the following two pieces of code will ends up with the same result but it isn't so.
Code1:

UPDATE t SET listColumn[2] = 7, listColumn[2] = 8  WHERE id = 1;

Expected result: listColumn={1,2,8,4}
Actual result: listColumn={1,2,7,8,4}

Code2:

UPDATE t SET listColumn[2] = 7  WHERE id = 1;
UPDATE t SET listColumn[2] = 8  WHERE id = 1;

Expected result: listColumn={1,2,8,4}
Actual result: listColumn={1,2,8,4}

So the question is why Code1 and Code2 give different results?
Looks like Code1 should give the same result as Code2.