如何从Hive读取HBase当前和先前版本的数据

Question

I want to read all the data from hbase table using Hive. Should be able to read all the Current and previous versions data from hbase

Answer 1

You can specify the number of version you get for Scan and Get and it will retrieve them:

HTable cTable = new HTable(TableName);
Get res = new Get(Bytes.toBytes(key));

//set no. of version that you want to fetch.
res.setMaxVersions(verNo);  <--

Result fetchRow = cTable.get(res);
NavigableMap<byte[], NavigableMap<byte[], NavigableMap<Long,byte[] >>> allVersions = fetchRow.getMap();

Note : Versioning is by default disabled while creating table. So, you need to enable it.

create 'employee',{NAME=>"myname",Versions=>2},'office' //Here versioning is enabled for column "myname" as "2" and no versioning for column "office"

describe 'employee'                                    // show you versioning information.

alter 'employee',NAME=>'office',VERSIONS =>4           // Alter

// Put and scan the table - it will show new and old value
put 'employee','1','myname:name','Jigyasa1'
put 'employee','1','myname:name','Jigyasa2'
put 'employee','1','office:name','Add1'
put 'employee','1','office:name','Add2'

scan 'employee',{VERSIONS=>10}

For Hbase-hive integration follow the ref. link : https://cwiki.apache.org/confluence/display/Hive/HBaseIntegration