[
https://issues.apache.org/jira/browse/CASSANDRA-10010?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15119631#comment-15119631
]
Sylvain Lebresne commented on CASSANDRA-10010:
----------------------------------------------
+1
> Paging on DISTINCT queries repeats result when first row in partition changes
> -----------------------------------------------------------------------------
>
> Key: CASSANDRA-10010
> URL: https://issues.apache.org/jira/browse/CASSANDRA-10010
> Project: Cassandra
> Issue Type: Bug
> Reporter: Tyler Hobbs
> Assignee: Benjamin Lerer
> Priority: Minor
> Fix For: 2.2.x
>
> Attachments: 10010-2.2.txt
>
>
> When paging, we always check new pages to see if they start with the same row
> that the previous page ended with, and if so, we trim that row to avoid
> duplicates. With {{DISTINCT}} queries, we only fetch the first row in each
> partition. If that row happens to change (it's deleted, or another row is
> inserted at the front of the partition) in between fetching the two pages,
> our check for a matching row will fail, resulting in a duplicate row being
> returned.
> It seems like the correct fix is to handle {{DISTINCT}} queries specially and
> only check to see if the partition key matches the last returned one instead
> checking that the rows match.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
