[
https://issues.apache.org/jira/browse/HBASE-10885?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14028994#comment-14028994
]
ramkrishna.s.vasudevan commented on HBASE-10885:
------------------------------------------------
We have this special case of visibility expression matching just to ensure that
we try to delete only the matching visibility tag, if again we do the normal
way of deleting also then may be we are not giving accumulo type of behaviour?
AnyPut is considered to be tagged with a visibility and so only a matching
delete should be used a tombstone I feel. BC break, in my perspective here is
that may be we are adding this functionality to define Delete behaviour
correctly in terms of Visibility exp.
Then for delete family also if once a visibiity expression matches.. from there
we could delete all the cells less that that particular version. That also
defines the right behaviour in terms of delete family combined with visibility
exp. In the current patch we only delete matching cells that are less than the
given ts.
bq.This way it works till 98.3 Now in 98.4 we will change this behavior. Is
that okey?
If we just give the old behaviour also then there is no point in all these
changes and this code should go only in major release only.
> 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
> Priority: Blocker
> Fix For: 0.99.0, 0.98.4
>
> Attachments: HBASE-10885_1.patch, HBASE-10885_2.patch,
> HBASE-10885_new_tag_type_1.patch, HBASE-10885_new_tag_type_2.patch,
> HBASE-10885_v1.patch, HBASE-10885_v2.patch, HBASE-10885_v2.patch,
> HBASE-10885_v2.patch, HBASE-10885_v3.patch
>
>
> 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.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
