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https://issues.apache.org/jira/browse/HBASE-10885?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13958607#comment-13958607
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ramkrishna.s.vasudevan commented on HBASE-10885:
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Doing like what ACL does may be easier because we could see which subject
issues the delete. If a super user/admin that makes the put does the delete
then we can just allow the delete to happen.
So assume we have user A with labels CONFIDENTIAL associated with him.
And there is a Put already done with row1, cf1, q1, CONFIDENTIAL and another
version
row1,cf1,q1, TOPSECRET&CONFIDENTIAL
If suppose user A tries to issue a delete ( not using Cellvisibility) - by
using the labels associated with User A we could find that we will not be able
to delete this row. Because one of the versions has additional labels
associated with it.
But allowing the delete to be added and then verifying the visibility
expression during compaction time - then we may have to handle the logic of
deletes and corresponding puts in the compaction scanner hook that we create.
Also what about the scans that happens? May be there is a matching delete for a
put with exactly same visibility expression, ideally the scan should not return
that KV.
Apart from this with the ACL delete handling case, some doubts regarding the
handling of the deleteColumn() - which deletes only the latest version. But
with the current implementation even though the current version allows the
delete with valid permissions for the user, because there is an older version
with lesser permission we deny the delete. Is that valid? same applies with
deleteFamily() also.
> 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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