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https://issues.apache.org/jira/browse/HBASE-10885?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13969688#comment-13969688
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Andrew Purtell commented on HBASE-10885:
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bq. Also it wont one simple bytes compare. A&B will be stored as one Tag. In 
case of '|' it will be stored as 2 tags. So we need to consider all these tags 
and compare all. Just a note before starting the impl.

Ok thanks Anoop.

> Support visibility expressions on Deletes
> -----------------------------------------
>
>                 Key: HBASE-10885
>                 URL: https://issues.apache.org/jira/browse/HBASE-10885
>             Project: HBase
>          Issue Type: Improvement
>    Affects Versions: 0.98.1
>            Reporter: Andrew Purtell
>            Assignee: ramkrishna.s.vasudevan
>             Fix For: 0.99.0, 0.98.2
>
>
> Accumulo can specify visibility expressions for delete markers. During 
> compaction the cells covered by the tombstone are determined in part by 
> matching the visibility expression. This is useful for the use case of data 
> set coalescing, where entries from multiple data sets carrying different 
> labels are combined into one common large table. Later, a subset of entries 
> can be conveniently removed using visibility expressions.
> Currently doing the same in HBase would only be possible with a custom 
> coprocessor. Otherwise, a Delete will affect all cells covered by the 
> tombstone regardless of any visibility expression scoping. This is correct 
> behavior in that no data spill is possible, but certainly could be 
> surprising, and is only meant to be transitional. We decided not to support 
> visibility expressions on Deletes to control the complexity of the initial 
> implementation.



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