Velocity

Velocity is the rate at which the data is being generated, or how fast the data is coming in. In simpler words, we can call it data in motion. Imagine the amount of data Facebook, YouTube, or any social networking site is receiving per day. They have to store it, process it, and somehow later be able to retrieve it. Here are a few examples of how quickly data is increasing:

• The New York stock exchange captures 1 TB of data during each trading session.
• 120 hours of videos are being uploaded to YouTube every minute.
• Data generated by modern cars; they have almost 100 sensors to monitor each item from fuel and tire pressure to surrounding obstacles.
• 200 million emails are sent every minute.

If we take the example of social media trends, more data means more revealing information about groups of people in different territories:

Velocity at which the data is being generated

The preceding chart shows the amount of time users are spending on the popular social networking websites. Imagine the frequency of data being generated based on these user activities. This is just a glimpse of what's happening out there.

Another dimension of velocity is the period of time during which data will make sense and be valuable. Will it age and lose value over time, or will it be permanently valuable? This analysis is also very important because if the data ages and loses value over time, then maybe over time it will mislead you.

Till now, we have discussed two characteristics of big data. The third one is variety. Let's explore it now.