Difference between H Base and RDBMS – Hadoop
H Base Vs RDBMS:-
|2. Flexible schema, add columns on the Fly||2. Fixed schema|
|3. Good with sparse tables.||3. Not optimized for sparse tables.|
|4. No query language||4. SQL|
|5. Wide tables||5. Narrow tables|
|6. Joins using MR – not optimized||6. optimized for Joins(small, fast ones)|
|7. Tight – Integration with MR||7. Not really|
|8. De-normalize your data.||8. Normalize as you can|
|9. Horizontal scalability-just add hard war.||9. Hard to share and scale.|
|10. Consistent||10. Consistent|
|11. No transactions.||11. transactional|
|12. Good for semi-structured data as well as structured data.||12. Good for structured data.|
Basis CRUD Operations in H Base:-
If you want any CRUD Operations in H Base, H Base should be up and running otherwise the operations will not be successful.
Running the child instance, but not running the master instance is not same as the running master instance as creating the child instance.
The initial sets of basic operations are often referred to as CRUD which stands for Create, Read, Update and Delete.
These are provided by the HTable class.
Whenever we are creating a table name in H Base, we must follow the below steps:
For creating a table, syntax is
h base (main):002:0>create ‘table name’, ’column family Name’
Ex:-h base (main):002:0>create ‘Hadoop Table’, ’column1’, ’column2’
We can’t delete column family names.
To inset data, the commands are
hbase (main):002:0> put ‘Hadoop Table’, ’row1’, ’ Hadoop: HDRS’, ‘For storage’
h base (main):002:0> put ‘Hadoop Table’, ’row2’, ’ Hadoop: Map Reduce’, For Processing’
h base (main):002:0> put ‘Hadoop Table’, ’row3’, ’ Hadoop: Hive’,’ For Ware house’
h base (main):002:0> put ‘Hadoop Table’, ’row4’, ’ Hadoop: H Base’,’ For Reads and write’
To see the data, command is
hbase (main):002:0> scan ‘Hadoop Table’, (like select stmt)
we can see the records of the table.
To get the particular row, cmd is
Hbase(main):002:0> get ‘Hadoop Table’, ‘row2’
To insert the multiple columns at a time, cmd is
h base (main):002:0> put ‘Hadoop Table’, ‘row4’ Hadoop: pig, hue, zookeeper’ ‘different components of hadoop’
To delete the row, cmd is
hbase(main):002:0> Delete ‘Hadoop Table’, ‘row4’‘Hadoop:Hive’
We can delete the complete row, but cannot delete the individual value of the row.
To insert the new row with same row key i.e with no over ride concept and it will append, Example as below
Hbase(main):002:0> put ‘Hadoop Table’, ‘row2’‘Hadoop:New map reduce’ ‘New one’
Based on the version ID, we will insert the values in H Base.
To check the count of records, cmd is
hbase(main):002:0> count ‘Hadoop Table’
To check whether the table is exist or not
H base(main):002:0> Exist ‘Hadoop Table’