Repository: hbase Updated Branches: refs/heads/master b9701d056 -> baaaac020
HBASE-9005 Improve documentation around KEEP_DELETED_CELLS, time range scans, and delete markers Project: http://git-wip-us.apache.org/repos/asf/hbase/repo Commit: http://git-wip-us.apache.org/repos/asf/hbase/commit/baaaac02 Tree: http://git-wip-us.apache.org/repos/asf/hbase/tree/baaaac02 Diff: http://git-wip-us.apache.org/repos/asf/hbase/diff/baaaac02 Branch: refs/heads/master Commit: baaaac020296e1587dd3b5f902caacdd612cfd88 Parents: b9701d0 Author: Misty Stanley-Jones <[email protected]> Authored: Thu Oct 2 09:21:58 2014 +1000 Committer: Misty Stanley-Jones <[email protected]> Committed: Tue Oct 7 14:05:13 2014 +1000 ---------------------------------------------------------------------- src/main/docbkx/schema_design.xml | 30 ++++++++++++++++++++++-------- 1 file changed, 22 insertions(+), 8 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/hbase/blob/baaaac02/src/main/docbkx/schema_design.xml ---------------------------------------------------------------------- diff --git a/src/main/docbkx/schema_design.xml b/src/main/docbkx/schema_design.xml index 40afefc..65e64b0 100644 --- a/src/main/docbkx/schema_design.xml +++ b/src/main/docbkx/schema_design.xml @@ -513,20 +513,34 @@ public static byte[][] getHexSplits(String startKey, String endKey, int numRegio <section xml:id="cf.keep.deleted"> <title> Keeping Deleted Cells </title> - <para>ColumnFamilies can optionally keep deleted cells. That means deleted cells can still be - retrieved with <link + <para>By default, delete markers extend back to the beginning of time. Therefore, <link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/Get.html";>Get</link> or <link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/Scan.html";>Scan</link> - operations, as long these operations have a time range specified that ends before the - timestamp of any delete that would affect the cells. This allows for point in time queries - even in the presence of deletes. </para> + operations will not see a deleted cell (row or column), even when the Get or Scan operation + indicates a time range + before the delete marker was placed.</para> + <para>ColumnFamilies can optionally keep deleted cells. In this case, deleted cells can still be + retrieved, as long as these operations specify a time range that ends before the timestamp of + any delete that would affect the cells. This allows for point-in-time queries even in the + presence of deletes. </para> <para> Deleted cells are still subject to TTL and there will never be more than "maximum number of versions" deleted cells. A new "raw" scan options returns all deleted rows and the delete markers. </para> - <para>See <link - xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/HColumnDescriptor.html";>HColumnDescriptor</link> - for more information. </para> + <example> + <title>Change the Value of <code>KEEP_DELETED_CELLS</code> Using HBase Shell</title> + <screen>hbase> hbase> alter ât1â², NAME => âf1â², KEEP_DELETED_CELLS => true</screen> + </example> + <example> + <title>Change the Value of <code>KEEP_DELETED_CELLS</code> Using the API</title> + <programlisting language="java">... +HColumnDescriptor.setKeepDeletedCells(true); +... + </programlisting> + </example> + <para>See the API documentation for <link + xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/HColumnDescriptor.html#KEEP_DELETED_CELLS"; + >KEEP_DELETED_CELLS</link> for more information. </para> </section> <section xml:id="secondary.indexes">
