Databases and big data

Big data means very large collections of data that are also varied and keep growing very fast. They are so big and complex, in size, in speed of growth and in variety, that the usual data management systems cannot store, process and analyse them. Data comes in three kinds. Structured data is tidy, like a table of marks. Unstructured data has no fixed shape, like pictures, voice recordings and free text. Semi-structured data lies in between: an e-mail has labels such as “To” and “Subject”, but its body is free text. Data grows quickly because digital technology develops quickly. Artificial intelligence uses and produces a lot of data. The internet of things, called IoT, means everyday objects connected to the internet that send data all the time, such as sensors. As data keeps growing, new big-data tools appear that help organisations to collect, process and analyse it fast enough to benefit from it. We give no size numbers, because the idea matters, not the figure.