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https://issues.apache.org/jira/browse/CASSANDRA-14910?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16699017#comment-16699017
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Aleksey Yeschenko commented on CASSANDRA-14910:
-----------------------------------------------

As spotted by [~ifesdjeen] during review, fixing comparison logic with static 
slices exposes another breakage - specifically the scenario when a static row 
is present in the sstable. With reversed comparator, when trying to read just 
the static row, such sstables would now be skipped.

Pushed the fix to the same branch.

> Don't skip entire sstables when reading backwards with mixed clustering 
> column order
> ------------------------------------------------------------------------------------
>
>                 Key: CASSANDRA-14910
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-14910
>             Project: Cassandra
>          Issue Type: Bug
>          Components: Local Write-Read Paths
>            Reporter: Aleksey Yeschenko
>            Assignee: Aleksey Yeschenko
>            Priority: Major
>             Fix For: 2.2.x
>
>
> In 2.x, if a table has clustering columns in {{DESC}} order, any SSTable that 
> doesn’t have any static rows in it will be skipped altogether when iterated 
> in reverse.
> This occurs due to the logic in {{ColumnSlice.compare()}} errorneusly sorting 
> any empty {{ByteBuffer}} after non-empty values due to the way 
> {{ReversedType}} operates. In case that empty {{ByteBuffer}} is coming from a 
> static {{Composite}}, however, the logic breaks down. Static {{Composite}} 
> components must *always* sort before any non-empty value, no matter the 
> table’s comparator.
> 2.0, 2.1, and 2.2 are all affected. 3.0 isn’t, but only because we skip slice 
> intersection logic entirely if static rows are present in the filter.
> Introduced by CASSANDRA-8502.



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