NoSQL and Advantages of NOSQL

Posted Posted in Cassandra, Hadoop, MongoDB

Why NoSQL?  – Bigger data handling capability   To handle Volume of data it allows data to be spread across commodity hardware  – Elastic scaling   Scale out the storage  – Flexible Schema/fixed data model    It does not need a organized schema. The schema is dynamic or fixed schema  – Integrated caching facility   To Increase performance, NOSQL […]

CAP Theorem

Posted Posted in Cassandra, Hadoop, Hadoop, HBase, MongoDB

CAP Theorem for a distributed architecture: Consistency: The data in database remains consistent after the execution of an operation.Example: After an insert operation all clients will see the same data Availability:The System is always On/Available. Partition Tolerance:The system continues to function even if the servers are not able to communicate with each other CAP provides […]

Data Manipulation Language in Cassandra

Posted Posted in Cassandra, Hadoop

Data Manipulation Language in Cassandra: Insert data to KeySpace: Syntax: &lt;INSERTSTATEMENT&gt; ::= INSERT INTO &lt;TABLENAME&gt; '(' &lt;IDENTIFIER&gt; ( ',' &lt;IDENTIFIER&gt;)* ')' VALUES'(' &lt;TERM -OR- LITERAL&gt; (',' &lt;TERM -OR- LITERAL&gt;)<em>')'(IF NOT EXIST)?( USING&lt;OPTION&gt; (AND&lt;OPTION&gt;)</em> )?&lt;TERM -OR- LITERAL&gt; ::= &lt;TERM&gt; | &lt;COLLECTION-LITERAL&gt; &lt;OPTION&gt; ::= TIMESTAMP &lt;INTEGER&gt;|TTL&lt;INTEGER&gt; Update data in KeySpace: Syntax: &lt;UPDATE-STMT&gt; ::= UPDATE&lt;TABLE-NAME&gt; (USING &lt;OPTION&gt; (AND […]

Data Definition Language in Cassandra

Posted Posted in Cassandra, Hadoop

Data Definition Language in Cassandra: You can create,alter,drop,truncate table/keyspaces in Cassandra. Create KeySpace: It is used to create a new keyspace Syntax: CREATE KEYSPACE &lt;NAME&gt; WITH STATEGY_CLASS = &lt;STATEGY_NAME&gt;[AND STRATEGY_OPTIONS;&lt;OPTION&gt;=&lt;VALUE&gt;[…]]; USE: It is used to switch to a keyspace to perform work Syntax: USE &lt;KEYSPACE&gt; Alter KeySpace: To change the existing keyspace Syntax: &lt;CRETAE-KEYSPACE-STMT&gt;::= ALTER […]

Cassandra Query Language (CQL)

Posted Posted in Cassandra, Hadoop

Cassandra Query Language:(CQL) CQL is the SQL interface in Cassandra.CQL is intended to privide a simple,common and easier interface in Cassandra. Cassandra was originally developed with a Thrift RPC based approach and it was difficult to work with. So CQL was developed to overcome the Thrift RPC approach. It is similar to SQL but all […]

Cassandra Data Model

Posted Posted in Cassandra, Hadoop

Data model determines the logical model of a database and the manner by which the data is stored, organized and manipulated. Data model Keywords in Cassandra: Cluster is the database server and keyspace is the database in cassandra.ROws and columns are the way data organized in a table in Cassandra.You can create primary and secondary […]

Snitches in Cassandra

Posted Posted in Cassandra, Hadoop

Snitch is used to determine the relative host proximity. Snitches gather information on network topology for cassandra to efficiently route requests. For a single data center cluster, simple snitch is sufficient. Types of Snitches: Simple snitches This is the default snitch used and uses a simple strategy of placing the copy of the row on […]