[ https://issues.apache.org/jira/browse/HBASE-10885?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13996785#comment-13996785 ]
Anoop Sam John commented on HBASE-10885: ---------------------------------------- Left some comments in RB. Review is not over. Will complete it soon. > 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, 0.98.3 > > Attachments: HBASE-10885_1.patch, HBASE-10885_2.patch, > HBASE-10885_new_tag_type_1.patch, HBASE-10885_new_tag_type_2.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)