In this section, we will discuss storing data that has been collected from various sources. Let's consider an example of crawling reviews of organizations for sentiment analysis, wherein each gathers data from different sites with each of them having data uniquely displayed.
Traditionally, data was processed using the ETL (Extract, Transform, and Load) procedure, which used to gather data from various sources, modify it according to the requirements, and upload it to the store for further processing or display. Tools that were every so often used for such scenarios were spreadsheets, relational databases, business intelligence tools, and so on, and sometimes manual effort was also a part of it.
The most common storage used in Big Data platform is HDFS. HDFS also provides HQL (Hive Query Language), which helps us do many analytical tasks that are traditionally done in business intelligence tools. A few other storage options that can be considered are Apache Spark, Redis, and MongoDB. Each storage option has their own way of working in the backend; however, most storage providers exposes SQL APIs which can be used to do further data analysis.
There might be a case where we need to gather real-time data and showcase in real time, which practically doesn't need the data to be stored for future purposes and can run real-time analytics to produce results based on the requests.