Hi,Jean-Marc, Thank you very much for you reply. You really solve my problem ! I`m using HBase0.94.2-cdh4.2.0, in this version I got only "truncate". But I still have a test cluster which is HBase0.98.1-cdh5.1.0, I found the "truncate_preserve" in Hbase0.98.
Next step I`ll going to find some JIRA patch for "truncate_preserve" and backport to my 0.94 cluster.