Repository: hbase
Updated Branches:
  refs/heads/master 1f5e93a8f -> 1bafe4a02


HBASE-8770 deletes and puts with the same ts should be resolved according to 
mvcc/seqNum


Project: http://git-wip-us.apache.org/repos/asf/hbase/repo
Commit: http://git-wip-us.apache.org/repos/asf/hbase/commit/1bafe4a0
Tree: http://git-wip-us.apache.org/repos/asf/hbase/tree/1bafe4a0
Diff: http://git-wip-us.apache.org/repos/asf/hbase/diff/1bafe4a0

Branch: refs/heads/master
Commit: 1bafe4a028a5291fc958c1deab2960e3ba33263c
Parents: 1f5e93a
Author: Michael Stack <st...@apache.org>
Authored: Thu Mar 1 23:51:08 2018 -0800
Committer: Michael Stack <st...@apache.org>
Committed: Tue Mar 6 11:34:08 2018 -0800

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 src/main/asciidoc/_chapters/datamodel.adoc | 35 +++++++++++++++++++++++++
 1 file changed, 35 insertions(+)
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http://git-wip-us.apache.org/repos/asf/hbase/blob/1bafe4a0/src/main/asciidoc/_chapters/datamodel.adoc
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diff --git a/src/main/asciidoc/_chapters/datamodel.adoc 
b/src/main/asciidoc/_chapters/datamodel.adoc
index 3674566..ba4961a 100644
--- a/src/main/asciidoc/_chapters/datamodel.adoc
+++ b/src/main/asciidoc/_chapters/datamodel.adoc
@@ -343,6 +343,7 @@ In particular:
 Below we describe how the version dimension in HBase currently works.
 See link:https://issues.apache.org/jira/browse/HBASE-2406[HBASE-2406] for 
discussion of HBase versions. 
link:https://www.ngdata.com/bending-time-in-hbase/[Bending time in HBase] makes 
for a good read on the version, or time, dimension in HBase.
 It has more detail on versioning than is provided here.
+
 As of this writing, the limitation _Overwriting values at existing timestamps_ 
mentioned in the article no longer holds in HBase.
 This section is basically a synopsis of this article by Bruno Dumon.
 
@@ -503,8 +504,42 @@ Otherwise, a delete marker with a timestamp in the future 
is kept until the majo
 NOTE: This behavior represents a fix for an unexpected change that was 
introduced in HBase 0.94, and was fixed in 
link:https://issues.apache.org/jira/browse/HBASE-10118[HBASE-10118].
 The change has been backported to HBase 0.94 and newer branches.
 
+[[new.version.behavior]]
+=== Optional New Version and Delete behavior in HBase-2.0.0
+
+In `hbase-2.0.0`, the operator can specify an alternate version and
+delete treatment by setting the column descriptor property
+`NEW_VERSION_BEHAVIOR` to true (To set a property on a column family
+descriptor, you must first disable the table and then alter the
+column family descriptor; see <<cf.keep.deleted>> for an example
+of editing an attribute on a column family descriptor).
+
+The 'new version behavior', undoes the limitations listed below
+whereby a `Delete` ALWAYS overshadows a `Put` if at the same
+location -- i.e. same row, column family, qualifier and timestamp
+-- regardless of which arrived first. Version accounting is also
+changed as deleted versions are considered toward total version count.
+This is done to ensure results are not changed should a major
+compaction intercede. See `HBASE-15968` and linked issues for
+discussion.
+
+Running with this new configuration currently costs; we factor
+the Cell MVCC on every compare so we burn more CPU. The slow
+down will depend. In testing we've seen between 0% and 25%
+degradation.
+
+If replicating, it is advised that you run with the new
+serial replication feature (See `HBASE-9465`; the serial
+replication feature did NOT make it into `hbase-2.0.0` but
+should arrive in a subsequent hbase-2.x release) as now
+the order in which Mutations arrive is a factor.
+
+
 === Current Limitations
 
+The below limitations are addressed in hbase-2.0.0. See
+the section above, <<new.version.behavior>>.
+
 ==== Deletes mask Puts
 
 Deletes mask puts, even puts that happened after the delete was entered.

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