what is meant by cassandra

>>what is meant by cassandra?

Google answers this one:
http://cassandra.apache.org/

Sorry but I cannot address the other questions.

>>what is meant by cassandra?
http://cassandra.apache.org/

Cassandra is typically associated with "big data", it is a so called NoSQL database because it does NOT adhere to the relational principles. So, it is really designed for fault tolerant 'distributed processing' and especially for high volume writes.  Cassandra claims "The largest known Cassandra cluster has over 300 TB of data in over 400 machines."

Apache Cassandra is an open source distributed database management system. It is an Apache Software Foundation top-level project[1] designed to handle very large amounts of data spread out across many commodity servers while providing a highly available service with no single point of failure. It is a NoSQL solution that was initially developed by Facebook and powered their Inbox Search feature until late 2010.[2][3] Jeff Hammerbacher, who led the Facebook Data team at the time, has described Cassandra as a BigTable data model running on an Amazon Dynamo-like infrastructure.[4]

http://en.wikipedia.org/wiki/Apache_Cassandra



>>when we go for casssandra?

Cassandra is a distributed key/value store where the keys and values can be anything and focus is more on making writes faster.

Generally people consider a NoSQL dbms for scaling and distribution. However the rationale should be based on more than "petabytes of data" with "faster reads/ writes". The focus should be on the type of the data you are managing. If the data is highly unstructured, a schema-less data store might make sense, even if you are not storing volumes of data. Alternatively if your data IS highly structured then there isnt a compelling case for NoSQL in most cases given the scalability of current Rdbms platforms already available.


>>what are the advantages of cassandra?
It's open source = advantage 1 I guess (but there are other open source products in the area).

But your question is too open: Measured against what? other NoSQL databases?

There are a growing number of commercial NoSQL dbms platform and it would take pages for a comparisonof products such as Mongo, Couch and others. Hadoop is of course the well known name in the "big data" arena.

I forgot this:
Consider the Apache Cassandra database
What are the pros and cons of this NoSQL database?

http://www.ibm.com/developerworks/library/os-apache-cassandra/os-apache-cassandra-pdf.pdf

Date: 03 Jul 2012

Consider to mongo db what are the advantages with cassandra

http://www.mongodb.org/
Mongo is often associated with "document storage" but I have no direct experience in this comparison, just industry reading:

Here are overview difference tables;
http://db-engines.com/en/system/Cassandra%3BMongoDB
http://vschart.com/compare/apache-cassandra/vs/mongodb
(+ you can add more into these tables)

Here are some useful references:

http://www.thoughtworks.com/insights/articles/nosql-comparison

http://www.networkworld.com/news/tech/2012/102212-nosql-263595.html

http://kkovacs.eu/cassandra-vs-mongodb-vs-couchdb-vs-redis

and this is a direct benchmark test of the 2
http://amesar.wordpress.com/2011/10/19/mongodb-vs-cassandra-benchmarks/

distributed key/value store  means what

scaling and distribution means what

Can you be more specific? What do you want to compare with?.

Is it between RDBMS vs no SQL or any product in specific.