Tuesday, 31 December 2013

HBase Examples

Go to HBase Mode
          $hbase shell

List all the tables
          hbase>list

Create HBase table with Normal Mode
          hbase>create ‘cars’, ‘vi’

Let’s insert 3 column qualifies (make, model, year) and the associated values into the first row (row1).
          hbase>put ‘cars’, ‘row1’, ‘vi:make’, ‘BMW’
          hbase>put ‘cars’, ‘row1’, ‘vi:model’, ‘5 series’
          hbase>put ‘cars’, ‘row1’, ‘vi:year’, ‘2012’

Now let’s add second row
          hbase>put ‘cars’, ‘row2’, ‘vi:make’, ‘Ferari’
          hbase>put ‘cars’, ‘row2’, ‘vi:model’, ‘e series’
          hbase>put ‘cars’, ‘row2’, ‘vi:year’, ‘2012’

Now let’s add third row
          hbase>put ‘cars’, ‘row3’, ‘vi:make’, ‘Honda’
          hbase>put ‘cars’, ‘row3’, ‘vi:model’, ‘f series’
          hbase>put ‘cars’, ‘row3’, ‘vi:year’, ‘2013’

Sacn the table
          hbase>scan ‘cars’

The next scan we’ll run will limit our results to the make column qualifier.
          hbase>scan ‘cars’, {COLUMNs=>[‘vi:make’]}

1 row to demonstrate how LIMIT works.
          hbase>scan ‘cars’, {COLUMNS =>[‘vi:make’], LIMIT => 1}

We’ll start by getting all columns in row1.
          hbase>get ‘cars’, ‘row1’

You should see output similar to:
COLUMN                   CELL
vi:make                 timestamp=1344817012999, value=bmw
vi:model                timestamp=1344817020843, value=5 series
vi:year                 timestamp=1344817033611, value=2012

To get one specific column include the COLUMN option.
         hbase>get ‘cars’, ‘row1’, {COLUMNS => ‘vi:make’}

You can also get two or more columns by passing an array of columns.
         hbase>get ‘cars’, ‘row1’, {COLUMNS => [‘vi:make’, ‘vi:year’]}

Delete a cell (value)
         hbase>delete ‘cars’, ‘row2’, ‘vi:year’

Let’s check that our delete worked
         hbase>get ‘cars’, ‘row2’

You should see output that shows 2 columns.
COLUMN    CELL
vi:make   timestamp=1344817104923, value=mercedes
vi:model   timestamp=1344817115463, value=e class 2
row(s) in 0.0080 seconds

Disable and drop tables
>disable ‘cars’

>drop ‘cars’

Exit the table
>exit

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