HBase

HBase is a database system that is built on top of HDFS. However the term ‘database’ might be a bit misleading. It is not a traditional SQL database that can be accessed by a traditional SQL type client, such as SQL developer.
HBase is a technique that falls in the area of no SQL, – Not Only SQL. This implies that other techniques must be used as we know from SQL type database.
One possible way to access this environment is via a shell. This shell can be invoked via “hbase shell”. If everything is set up correctly, one sees something like:

A command to see which tables are available is given via “list”:

hbase(main):004:0> list
TABLE                                                                                                                                                        
emp                                                                                                                                                          
1 row(s) in 0.1520 seconds

=> ["emp"]

Here, we see that a table “emp” exists. On may investigate the content via “scan ’emp'”:

hbase(main):005:0> scan "emp"
ROW                                      COLUMN+CELL                                                                                                         
 1                                       column=naam:, timestamp=1528294868410, value=tom                                                                    
 1                                       column=naam:voornaam, timestamp=1528294898266, value=jan                                                            
 1                                       column=nummer:, timestamp=1528294834043, value=1                                                                    
 2                                       column=naam:voornaam, timestamp=1528296099663, value=flip                                                           
2 row(s) in 0.0320 seconds

hbase(main):006:0> 

One may subsequently insert new data via a put command. In this command, we must mention the table (here emp), the row (here 2), the field (here naam:voornaam) and the actual value.

hbase(main):002:0> put 'emp',2,'naam:voornaam','flip'
0 row(s) in 0.0840 seconds