A database is simply a structured and systematic way of storing information to be accessed, analyzed, transformed, updated and moved (to other databases).
To begin understanding databases, consider an Excel notebook or Google sheet. Spreadsheets like these are a basic form of a table. Databases are almost exclusively organized in tables and those tables have rows and columns. So, think of a simple database as a collection of spreadsheets (or tables) joined together in a systematic way.
Databases are stored on servers either on-premises at an organization’s office or off-premises at an organization’s data center (or even within their cloud infrastructure). Databases come in many formats in order to do different things with various types of data.
What Are Databases Used For?
- Holding data efficiently
- Allowing smooth online transactions
- Updating information quickly
- Simplifying data analysis
Why Do We Use Databases?
Computerized databases were first introduced to the world in the 1960s and have since become the foundation for products, analysis, business processes and more. Many of the services you use online everyday (banking, social media, shopping, email) are all built on top of databases.
We use and rely on databases for many reasons.
Databases Hold Data Efficiently
We use databases because they are an extremely efficient way of holding vast amounts of data and information. Databases around the world store everything from your credit card transactions to every click you make within one of your social media accounts. Given there are nearly eight billion people on the planet, that’s a lot of data.
Databases Allow Smooth Transactions
Databases allow access to various services which, in turn, allow you to access your accounts and perform transactions all across the internet. For example, your bank’s login page will ping a database to figure out if you’ve entered the right password and username. Your favorite online shop pings your credit card’s database to pull down the funds needed for you to buy that Snuggie you’ve been eyeing.
Databases Update Information Quickly
Databases allow for easy information updates on a regular basis. Adding a video to your TikTok account, directly depositing your salary into your bank account or buying a plane ticket for your next vacation are all updates made to a database and displayed back to you almost instantaneously.
Databases Simplify Data Analysis
Databases make research and data analysis much easier because they are highly structured storage areas of data and information. This means businesses and organizations can easily analyze databases once they know how a database is structured. Common structures (e.g. table formats, cell structures like date or currency fields) and common database querying languages (e.g. SQL) make database analysis easy and efficient.
What Is a Database Management System?
A database management system (DBMS) is a software package we use to create and manage databases. In other words, a DBMS makes it possible for users to actually interact with the database. In other words, the DBMS is the user interface (UI) that allows us to access, add, modify and delete content from the database. There are several types of database management systems, including relations, non-relational and hierarchical.
3 Types of Databases
There are many types of databases and several of them are offshoots of the major database types, so we can consider that all databases fall into one of three large groupings.
1. Hierarchical Databases
Hierarchical databases were the earliest form of databases. You can think of these databases like a simplified family tree. There’s a singular parent object (like a table) that has child objects (or tables) under it. A parent can have one or many child objects but a child object only has one parent. The benefit of these databases are that they’re incredibly fast and efficient plus there’s a clear, threaded relationship from one object to another. The downside to hierarchical databases is that they’re very rigid and highly structured.
2. Relational Databases
Relational databases are perhaps the most popular type of database. Relational databases are set up to connect their objects (like tables) to each other with keys. For example, there might be one table with user information (name, username, date of birth, customer number) and another table with purchase information (customer number, item purchased, price paid). In this example, the key that creates a relationship between the tables is the customer number.
3. Non-Relational Databases
Non-relational databases were invented more recently than relational databases and hierarchical databases in response to the growing complexity of web applications. Non-relational databases are any database that doesn't use a relational model. You might also see them referred to as NoSQL databases. Non-relational databases store data in different ways such as unstructured data, structured document format or as a graph. Relational databases are based on a rigid structure whereas non-relational databases are more flexible.
What Are the Components of a Database?
Components of a database vary slightly depending on whether the database is hierarchical, relational or non-relational. However, here’s a list of database components you might expect to be associated with any database.
Schema
The database schema is essentially the design of the database. A schema is developed at the early conceptual stages of building a database. It’s also a valuable source of ongoing information for those wanting to understand the database’s design.
Constraints and Rules
Databases use constraints to determine what types of tables can (and cannot) be stored and what types of data can live in the columns or rows of the database tables, for example. These constraints are important because they ensure data is structured, less corruptible by unsanctioned data structures and that the database is regulated so users know what to expect. These constraints are also the reason why databases are considered rigid.
Metadata
Metadata is essentially the data about the data. Each database or object has metadata, which the database software reads in order to understand what’s in the database. You can think of metadata as the database schema design and constraints combined together so a machine knows what kind of database it is and what actions (or can’t) be performed within the database.
Query Language
Each database can be queried. In this case, “queried” means people or services can access the database. That querying is done by way of a particular language or code snippet. The most common querying language is SQL (Structured Query Language) but there are also many other languages and even SQL variations like MySQL, Presto and Hive.
Objects
Each database is a collection of objects. There are a few different types of objects stored within databases such as tables, views, indexes, sequences and synonyms. The most well known of these are tables, like spreadsheets, that store data in rows and columns. You may also hear the term “object instance,” which is simply an instance or element of an object. For example, a table called “Transactions” in a database is an instance of the object-type table.
Database Advantages
- Improved data sharing and handling
- Improved data storage capacity
- Improved data integrity and data security
- Reduced data inconsistency
- Quick data access
- Increased productivity
- Improved data-driven decision making
Database Disadvantages
- High cost
- High complexity
- Required dedicated database management staff
- Risk of database failure
