Hi Narayanan,
I think you need to create the table with versions enabled.
For example, if you need to store 5 versions, you can use create like this:
Hbase> create 'useractivity', {NAME => 'pageviews', VERSIONS => 5}
HBase> put 'useractivity', 'userid1', 'pageviews:uri',
'http://www.allaboutdata.net'
HBase> put 'useractivity', 'userid1', 'pageviews:uri', 'http://www.yahoo.co.in'
HBase> get "useractivity", "userid1", {COLUMN=>'pageviews',VERSIONS=>2}
COLUMN CELL
pageviews:uri timestamp=1310367267049,
value=http://www.yahoo.co.in
pageviews:uri timestamp=1310367221129,
value=http://www.allaboutdata.net
2 row(s) in 0.0440 seconds
One thing you need to watch out for is the VERSIONS is defined on column
family, and hence, you cannot change it once you have defined your column
family. This will work if your applications wishes to store only fixed number
of versions you want to store. If that is not the case, you need to relook at
your table design and realize that using some other way.
Regards,
Srikanth
-----Original Message-----
From: Narayanan K [mailto:[email protected]]
Sent: Monday, July 11, 2011 11:07 AM
To: [email protected]
Subject: Fetching and iterating through all column values belonging to all
Timestamps of a Row
Hi all,
I am using Hadoop - 0.20.1 and HBASE - 0.20.
Currently, I am trying to retrieve and iterate through all the column values
of a particular rowkey in an Hbase Table.
But I am able to retrieve *only* the cell+value having the *latest Timestamp
*.
Eg:
*hbase>create 'useractivity', 'pageviews'
hbase>put 'useractivity', 'userid1', 'pageviews:uri',
'http://www.allaboutdata.net'
hbase>put 'useractivity', 'userid1', 'pageviews:uri', 'http://www.yahoo.co.in'*
*hbase>get 'useractivity', 'userid1' *
is fetching only the "http://www.yahoo.co.in"; column value as it has the
latest timestamp.
I wanted to view both the values in the column *uri*.
I tried the same with the java API - Get as well as Scan. But still both of
them gave me the same result with the column having value that was
inserted the latest.
I also read through some old archives and found I could setTimeRange on
Get/Scan which is also not solving my problem.
*get.setTimeRange(0,Long.MAXVALUE);* as in :
*HTable table = new HTable(new HBaseConfiguration(), "useractivity");
Get get = new Get(Bytes.toBytes("userid1"));
get.addFamily(Bytes.toBytes("pageviews"));
get.setTimeRange(0,Long.MAXVALUE);
Result result = table.get(get);
byte[] value = result.getValue(Bytes.toBytes("pageviews"),
Bytes.toBytes("uri"));
System.out.println(Bytes.toString(value));*
This is fetching me only the column value with the latest timestamp.
I tried the same with Scan API. But I get the same result.
*Could you please let me know how I can retrieve all column values of all
timestamps of a particular rowkey??*
Many Thanks,
Narayanan
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