Cassandra Group By clause in Select command

1. Go to C:\Program Files\DataStax-DDC\apache-cassandra\conf\cassandra.yaml
change false to true

enable_user_defined_functions: true


2. Paste below functions in cqlsh window

CREATE OR REPLACE FUNCTION state_group_and_count( state map, type text )
CALLED ON NULL INPUT
RETURNS map
LANGUAGE java AS '
Integer count = (Integer) state.get(type);  if (count == null) count = 1; else count++; state.put(type, count); return state; ' ;

CREATE OR REPLACE AGGREGATE group_and_count(text)
SFUNC state_group_and_count
STYPE map 
INITCOND {};


3. execute the query like below

--select group_and_count(column) from table;
-- ex
-- select group_and_count(item) from skutable;



4. you may see like this 
Failed to format value OrderedMapSerializedKey([(u'xxx', 4)]) : 'NoneType' object has no attribute 'sub_types'
this is a cqlsh error. so you can try from programming languages like java..., it may work perfectly.

linux Ubuntu Postgresql Setup Installation

Type the below commands.

postgresql
**********
    sudo apt-get install postgresql postgresql-contrib
    apt-cache search postgres
    sudo apt-get install pgadmin3


create default user/role postgres
**********************************
    sudo -u postgres psql postgres
    \password postgres
    p0stgr3s
    p0stgr3s

linux Ubuntu SVN Setup Installation

svn
***
Type the below commands.
**********************

    sudo apt-get install subversion apache2 libapache2-svn

checkout
********
    svn co --username vijay svn://182.71.255.164/svn/repos/FastRaq/trunk/3.Implementation/Code/middleware
    enter pwd

linux Ubuntu Maven Setup Installation

Maven
*****
Type the below commands.

    sudo apt-get install maven
    sudo update-alternatives --config mvn

linux Ubuntu JDK Java Setup Installation

java 1.8
*******

Type the below commands.

    Installing Java 8
        $ sudo add-apt-repository ppa:webupd8team/java
        $ sudo apt-get update
        $ sudo apt-get install oracle-java8-installer
    Verify java
        $ java -version
    Configuring Java Environment
        $ sudo apt-get install oracle-java8-set-default

linux Ubuntu Git Setup Installation

Git
***
Type the below commands.

    sudo apt-get install git-core
    git clone https://github.com/ebhaiah/middleware-soa.git

Linux - Ubuntu - Mongodb Installation Setup

mongodb
*******


1.    Install MongoDB
    Import the public key used by the package management system.

    sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 7F0CEB10

2Create a list file for MongoDB.

    echo "deb http://repo.mongodb.org/apt/ubuntu trusty/mongodb-org/3.0 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.0.list

3 Reload local package database.

    sudo apt-get update

4 Install the MongoDB packages.

    sudo apt-get install -y mongodb-org

4.1 Install a specific release of MongoDB.

    sudo apt-get install -y mongodb-org=3.0.7 mongodb-org-server=3.0.7 mongodb-org-shell=3.0.7 mongodb-org-mongos=3.0.7 mongodb-org-tools=3.0.7

5. Start MongoDB.

    sudo service mongod start

5.1 Verify that MongoDB has started successfully
    Verify that the mongod process has started successfully by checking the contents of the log file at /var/log/mongodb/mongod.log for a line reading

6 Stop MongoDB.

    sudo service mongod stop

7 Restart MongoDB.
   
    sudo service mongod restart

8. mongodb - uninstall

    sudo service mongod stop
    sudo apt-get purge mongodb-org*
    sudo rm -r /var/log/mongodb
    sudo rm -r /var/lib/mongodb