Understanding Database Design in General and 3-Layer Architecture

If you are new to enterprise database management, then you have to first learn the fundamentals of database design by covering the:

  • Requirement analysis
  • Requirement specification
  • Semantic or conceptual DB design
  • Design of logical schema
  • Physical schema design
  • DB optimization, and finally
  • Database administration

Requirement analysis and specification

At this phase of database design, you may be doing a detailed analysis with an objective to understand the exact enterprise database needs. A requirement document must be prepared first, which should cover the types of data to handle, storage needs, and different data items related to each other. Segmenting it will make things easier to handle for you in the long run. 

Once the requirement analysis is done, you can further define the elements in more detail by specifying different attributes. Once it is completed, you can further make a specification document. For information gathering at this stage, you can analyze the objectives, requirements of various users, visit the site, and check the Joint Applications Design and Joint Requirements Analysis.

Conceptual database design

During this stage, you may further model the requirement analysis with another higher-level abstraction. This should cover all the entities, relationships, and attributes. This conceptual design will act as the base of a permanent description of your final DBMS requirements. This schema needs to contain all the entities in data relationships and information about data constraints.

Logical schema design

After identifying all the conceptual design needs and the data relations and dependencies, the data need to be arranged in a logical model by mapping the DBMS tables. You may perform a normalization for defining the relations in the respective normal forms. For this, you may have to map the regular, weak, associative, binary, ternary, unary, supertype, subtype entities, etc., with their relationships. For those who are confused about choosing the best database schema for your enterprise DB, it is ideal for supporting reliable consultants like RemoteDBA.com. Let us further discuss the three-layer database architecture in detail 

3-layer Design model

In the case of 3-tier database architecture, the database functions are executed at three different layers. We may have a detailed look into the three-tier architecture further.

Tier 1 of the Presentation layer

The first layer of the three-tier architecture is the presentation layer, which is also considered the front-end of this system. Usually, this front-end layer consists of a user interface. This is a flexible layer, a graphical interface that the users can access through a web browser or application. It can display the information needed for the end-users. This tier is built with any of the web development languages like HTML, CSS, JS, and other programming languages. This layer can also effectively communicate with the underlying layers through API calls.

Tier 2 of Application layer

The immediate next layer is known as the applications layer, which consists of the business logic. Which means, this layer defines the functional objective of the application. Enterprises can include their core competencies to be actualized through this layer. This layer will help derive the functional objectives of a business. Tier 2 is coded in any functional programming languages for application development like PHP, Java, .NET, Python, C#, or CPP, etc.

Tier 3 of the Data layer

The data layer is the final layer in a 3-tier architecture, which is the system’s actual functional database. This primarily functions as the storage system of the enterprise application and the access layer. The standard entities of tier 3 are standard relational or non-relational databases. These are mostly MySQL, Oracle, PostgreSQL, Cassandra, MS SQL Server, Maria DB,MongoDB, etc.Enterprise data stored in this layer can be accessed using API calls through the application layer.

Three-tier architecture deployment model

In a three-tier database application architecture, one may follow the deployment modality as discussed below.

The first layer or the presentation layer is deployed at the end-user machine. It can be a laptop, desktop, or even a smartphone. The users can access their web browser or desktop application to activate it. This layer can also be integrated with a mobile application from which the user can get the user interface and get connected to the other layers over the internet. Usually, the interface layer is operated over a web application through a web server.

The subsequent layer or application layer, which lies beneath the presentation layer, is usually hosted on one more application servers. These are also hosted on the cloud or some dedicated workstations based on the complexity and processing power needed for the application. 

In the next layer, which is the third layer of the 3-tier architecture, which the data layer comprises single or multiple databases, which can be either relational or non-relational DBs. There may also be data sources of big data, data lakes, or database management systems hosted on on-premise or cloud.

Choice of the underlying database

Choice of an enterprise database is now an important choice, which needs to be made based on your business objectives. Conventionally, this was SQL-based relational DBs, but now with the need for big data management and enabling machine learning capabilities, databases need to have a higher storage capacity.

Considering this need, you may also consider deploying NoSQL databases, which offers higher scalability to accommodate a huge data volume. Going a step ahead, the modern-day database also needs to support analytical applications as businesses largely depend on data-based decision making lately.  When you start as a small organization, literally any database may work for you, and this may limit many from thinking much serious about it. 

However, as the organization grows, the volume of data may grow to a larger extent, and you may find it out that you are in trouble with the wrong choice made. When your data grows exponentially, the challenges related to your technology infrastructure also matter a lot. So, it is important to make the right scalable choices at the first point itself while choosing database technologies to have a smooth journey as you go forward.

Author’s Bio: Walter Moore is a writer and notable management and digital marketing expert. He is an experienced digital marketer who has helped e-commerce businesses in all niches gain with his effective marketing strategies and guidance