Many have known that the cost server equipment, maintenance and manpower allocation are costly. Furthermore, with the rising cost of server maintenance, electrical cost, manpower cost. New technologies such as cloud computing were introduced to provide alternatives to new and existing companies. One of the cloud computing solutions, cloud database is one of them which propose to move high costly database to be maintain by specialize company. Hence, cost saving on maintenance, equipment, manpower and electricity are solved.
In this report, we will be discussing on the concept of cloud database, its advantages and disadvantages and security challenges that companies may face ...view middle of the document...
As a result, these companies may not have assurance with the service provider who manage their data centers and having their data floating in the cloud. 
2.1. Structure of Cloud Database
The data stores in the cloud database holds on different data centers. These data centers are located at different locations in any part of the world. This also makes the cloud database structure different from the Rational Database Management Systems (RDBMSs) and its structure into a complex one. There are multiple nodes through a cloud database, designed for query services, data centers that are located in various locations and those corporate data centers as well. The mandatory of such linkages makes easy to access to the database over the cloud. As such, there are various method for accessing the database over the cloud services. The user can make use of devices such as computer, notebook, mobile phone or even tablets through the internet to access the cloud database. 
In the case where the user accesses the cloud database by a computer with internet, the internet becomes the joining point which plays its role as a bridge among the data centers. There are more than one nodes being used in the cloud database where it is important not to relay on just one node. A single node can handle any kind of the query created by the user as peer to per communication has implemented.
In Figure 1, it explains how the basic architecture of the cloud database works between the user and the database over the cloud services. In depth, it also explains how the specific node take caution of the query which the user has created and respond to the user.
2.2. Cloud Database Services
There are several different kind of cloud database service providers who are working to provide DBaaS that are separated into three major categories. These three major categories are non-rational database, rational database and operating virtual machine embedded with database software like SQL. From other point of view, they can be known as NoSQL, Native, or Hybrid. [2, 3, 4, 5]
â€¢ Install and Manage
The administrator or developer will selects their database, install it and create its instance in their cloud. After such have been implemented, he/she will then responsible for all administration tasks.
â€¢ Cloud-Managed DBaaS Instance
The cloud provider proposals a Database Management Systems (DBMS) service that some develops just use it. All sorted of administration are performed by the cloud provider. As a result, the developer only need to worry about the operational tuning issues such as tables, query optimization, roles and privileges assignments, indices, etc.
â€¢ External Cloud-Agnostic DBaaS Solution
Such typical solutions used NoSQL databases where users administered through web interface with specified port number(s). As such, it provides the user a high level of cloud independence which also depend on the provider, as well as multi-cloud availability and...