Data Warehouse: Overview and Benefits

Francesco Sessa
4 min readMay 29, 2020
Illustration by Giorgia Lupi
Illustration by Giorgia Lupi


Hi, I’m Francesco, this is my first post on medium, I work as a Back-end Developer for Abiby. Abiby is the most exclusive Italian subscription service that allows its members to discover, try and buy new beauty brands. Each month’s box offers something exciting to try, whether it’s the latest in skincare from around the world or seasonally themed makeup.

In the last year, I have had the opportunity to develop a Data Warehouse to support Abiby’s business.

In this article, I would like to present a brief overview of the data warehouse and why it’s necessary to invest in it.

What is Data?

Before anything else, there is always data. The word “data” comes from the Latin “datum”: “a piece of information (…) from which inferences may be drawn” and/or “a fixed starting point of a scale or operation”.

Data is embodied in everything: from the creation of the Universe and all living creatures to inanimate objects and man-made products. It is in atoms and the information which all things are made of and the way that information is stored and organized.

Let’s take a look at one example: A written document. It is filled with information (data) and information about the information (metadata). It has text, it may contain images, it has a date of creation, one or more authors, a number of pages and words written in it, the document is created in a specific document format and stored in one or more places and its about particular topics.

Data is the foundation of data science; it is the material on which all the analyses are based. In the context of data science, there are two types of data: traditional, and Big Data.

Traditional data is data that is structured and stored in databases that analysts can manage from one computer; it is in a table format, containing numeric or text values.

Big Data, on the other hand, is… bigger than traditional data, and not in a trivial sense. From variety (numbers, text, but also images, audio, mobile data, etc.), to velocity (retrieved and computed in real-time), to volume, big data is usually distributed across a network of computers.

What is a Data Warehouse?

First, what is a warehouse in general terms? It is a large space to store things in. By definition, a subject-oriented, integrated, time-variant collection of data. More specifically, the process of creating that can be seen as moving raw data input via Extract-Transform-Load actions into a consolidated storage system to be used for analysis.

A Data Warehouse is:

  • Subject Oriented: Data is categorized and stored by business subject rather than by application.
  • Integrated: Data on a given subject is collected from disparate sources and stored in a single place.
  • Time-variant: Data is stored as a series of snapshots each representing a period of time.
  • Non-volatile: Typically data in the data warehouse is not updated or deleted.

Why Invest In A Data Warehouse?

For a company to be successful in the future, it must make good decisions. And to make good decisions requires all relevant data to be taken into consideration. And the best source for that data is a well-designed data warehouse.

Generally speaking, data warehouses provide the following benefits to enterprises.

Faster and more flexible reporting

While on the one hand data warehousing allows you to collect, consolidate, and create reports in real-time, on the other it creates a repository of historical information on all the variables that affect profitability. This faster and more flexible data reporting mechanism allows us to habitually carry out comparative and competitive analyzes to evaluate the effectiveness of the services provided, the level of customer satisfaction, slow-moving products or non-performing activities, areas to be improved, finding mistakes before they can cost the company a serious loss in terms of money or reputation, identifying market trends, and introducing product lines in line with the needs of emerging customers and far ahead of the competition.

Quick and easy access to data

Speed is an important factor that sets you above your competitors. Business users can quickly access data from multiple sources from a data warehouse, meaning that precious time won’t be wasted on retrieving data from multiple sources. This allows you to make quick and accurate decisions, with little or no support from your IT department.

Improving integration

An organization registers data in various systems that support the various business processes. In order to create an overall picture of business operations, customers, and suppliers, thus creating a single version of the truth the data must come together in one place and be made compatible. Both external (from the environment) and internal data (from ERP, CRM, and financial systems) should merge into the Data Warehouse and then be grouped.

Data quality and consistency

Since data warehouses gather information from different sources and convert them into a single and widely used format, departments will produce results that are in line and consistent with each other. When data is standardized, you can have confidence in its accuracy, and accurate data is what makes for strong business decisions.

Developing a data warehouse has helped Abiby make better business decisions. Data warehousing improves the speed and efficiency of access to different data sets and makes business decisions easier and they guide us in business and marketing strategies, which are essential to distinguish us from the competition.

Data warehouses provide a lot of advantages. They allow companies to analyze their data effectively as well as trust it!

More articles coming soon...



Francesco Sessa

Startup Tech Advisor and Software Engineer | Founder at a | 27y — Milan, Italy | Passions: 👨🏻‍🍳 ✈️ 🎭 👨🏻‍💻 🕺🔭 🏔