Customers can access the database from the cloud database service provider through the Internet and deliver it to users when they need it. In other words, cloud databases are designed for virtualized computer environments. Cloud database is implemented using cloud computing, that is, using the software and hardware resources of cloud computing service providers. Cloud computing is growing rapidly in the global IT industry. Many companies have started turning to cloud computing and accessing data from cloud databases. One survey showed that nearly 36% of companies run applications through cloud services (Mimecast Survey, 2011). Cloud computing can be called a new dimension in the IT world in terms of cloud database cost savings and faster application performance. This trend among enterprises indicates that in the near future, enterprises will start to rely on cloud applications. Cloud databases are mainly used as services. It is also known as Database as a Service (DBaaS). Cloud database will become the most commonly used technology for storing massive data by many enterprises around the world. It's not as simple as taking a relational database and deploying it on a cloud server. Not only that. This means adding additional nodes online when needed and improving the performance of the database. Data needs to be distributed across different data centers located in different locations. The database must be accessible at all times so that users can obtain data whenever they need it. Cloud databases must be easy to manage and should also reduce costs (Curino, Madden, etc.). Cloud computing is very effective in recovering information after a database disaster. As the demand and technological advancements continued to increase, cloud database usage patterns were invented. At the beginning of the cloud database, customers accessing the cloud database could only use the read facility. However, depending on the client's requirements, writing queries is also involved. The introduction of Web 2.0 made this possible. It is observed that the number of read requests to the database is still greater than the number of write requests. But in the near future, as business applications also rely on cloud computing, the number of reads from cloud databases will also increase (Hogan, 2008). This trend has begun to narrow the gap between read and write requests to cloud databases.
