Version
You can check the version of Cassandra you are using by running the command
cqlsh -v
in your command line. This will display the version of Cassandra you are running.
About Apache Cassandra
Cassandra is a NoSQL database developed by the Apache Software Foundation written almost entirely in Java.
Twitter is a very notable user of this database software. It was launched in 2008 for the first time,
and it has since evolved to be what it is today.
Cassandra belongs to the family of NoSQL databases. A NoSQL database has very specific advantages and
differences
to the usual relational database management system model, mostly consulted in SQL. For example, when a database
is not relational,
one can include data points in it which have unknown types of data. With a SQL relational database,
it is imperative that a data structure is written and traced out before entering new points.
Cassandra does not have these limitations and is in turn extremely quick and high performing with retrieving
data for reasons that we will expand upon below.
Cassandra is a database used to warehouse big amounts of data, which can often have a semi-structured or no
structured characteristic.
This database software is very well-known for being maintained with 4 independent nodes all with the same copy
of data and retrieval capacities.
That means that if the main node should fail, there are other backups that allow the data to keep running,
being processed and received without downtime. Therefore, Cassandra is used by big technology companies
or small businesses/individuals that need to store their data in a way they know will never be lost.
Some characteristics of Cassandra are worth noting. For example, Cassandra is scalable not only vertically,
meaning that it can warehouse enormous data points collected in extremely high frequencies (minutes or even
seconds),
but it is also horizontally scalable, which all SQL-based database software struggles with with a lot to do.
This means that if a Cassandra user stores the time at which ice cream was sold, and the flavor that it was,
but later decides that he wants to know the price of it this can be done extremely simply with Cassandra,
without having to migrate the entire database to a new frame, which is the case with relational SQL
models.
Releases
Cassandra is currently on the stable release of 3.11.7, released on the 25th of July, 2020. Version 4.0 is on
the way,
known as a release candidate, but has no clear date of being available to the public,
and also the main additions and features are still not known.