When a Delete occurs, an insert is made with the timestamp being the current time (to indicate it is the latest version). Hence, when you insert a value after this with an _older_ timestamp, it is not taken in as the latest version, and is hence ignored when scanning. This is why you do not see the data.
If you instead insert this after a compaction has fully run on this store file, then your value will indeed get shown after insert, cause at that moment there wouldn't exist such a row with a latest timestamp at all. hbase(main):060:0> flush 'test-table' 0 row(s) in 0.1020 seconds hbase(main):061:0> major_compact 'test-table' 0 row(s) in 0.0400 seconds hbase(main):062:0> put 'test-table', 'row4', 'test-family', 'value', 10 0 row(s) in 0.0230 seconds hbase(main):063:0> scan 'test-table' ROW COLUMN+CELL row4 column=test-family:, timestamp=10, value=value 1 row(s) in 0.0060 seconds I suppose this is why it is recommended not to mess with the timestamps manually, and instead just rely on versions. On Tue, Aug 14, 2012 at 8:24 PM, Takahiko Kawasaki <daru...@gmail.com> wrote: > Hello, > > I have a problem where 'put' with timestamp does not succeed. > I did the following at the HBase shell. > > (1) Do 'put' with timestamp. > # 'scan' shows 1 row. > > (2) Delete the row by 'deleteall'. > # 'scan' says "0 row(s)". > > (3) Do 'put' again by the same command line as (1). > # 'scan' says "0 row(s)" ! Why? > > (4) Increment the timestamp value by 1 and try 'put' again. > # 'scan' still says "0 row(s)"! Why? > > The command lines I actually typed are as follows and the attached > file is the output from the command lines. > > scan 'test-table' > put 'test-table', 'row3', 'test-family', 'value' > scan 'test-table' > deleteall 'test-table', 'row3' > scan 'test-table' > put 'test-table', 'row3', 'test-family', 'value' > scan 'test-table' > deleteall 'test-table', 'row3' > scan 'test-table' > put 'test-table', 'row4', 'test-family', 'value', 10 > scan 'test-table' > deleteall 'test-table', 'row4' > scan 'test-table' > put 'test-table', 'row4', 'test-family', 'value', 10 > scan 'test-table' > put 'test-table', 'row4', 'test-family', 'value', 10 > scan 'test-table' > quit > > Is this behavior the HBase specification? > > My cluster is built using CDH4 and the HBase version is 0.92.1-cdh4.0.0. > > Could anyone give me any insight, please? > > Best Regards, > Takahiko Kawasaki -- Harsh J
