What is a Data Warehouse?

-

 

What is a Data Warehouse?

Have you ever thought about where all the information generated across industries is kept? Every day, the world produces billions of megabytes of data, and that number continues to rise. In this lesson, we’ll explore how data warehouses store this information in a centralized location and allow organizations to use it effectively.
Let’s dive straight in.

What is a Data Warehouse?


A Data Warehouse (DWH) is a key element of a business intelligence ecosystem, designed to help users carry out analytical tasks and examine large datasets. It brings together information from a variety of sources—including transactional systems, application logs, and more. A DWH often acts as the organization’s authoritative source of data.

You can think of it as a dedicated environment that supports management by holding vast amounts of historical information. By evaluating this data, a DWH enables companies to make more informed and strategic choices.

 

A picture containing graphical user interface Description automatically generated

 

Characteristics Of a Data Warehouse:

Data warehouses are defined by four major characteristics, each of which supports effective analysis and decision-making.

1. Subject-oriented

This means the data warehouse is organised around a particular theme or area of interest, rather than day-to-day business operations. It concentrates on a specific subject and provides a clear, focused summary by filtering out irrelevant details that do not contribute to analysis.

2. Time-variant

A DWH stores data in relation to specific time periods. Information is added at fixed intervals—such as hourly, weekly, or monthly—and remains unchanged for the duration of that time slice. This allows analysts to observe trends and track changes over time.

3. Non-volatile

Once data is written to the warehouse, it is not removed or altered. Because the DWH is separate from operational systems, frequent updates happening in day-to-day databases do not overwrite historical records. This stability helps analysts understand past events clearly.

4. Integrated

Integration means that the warehouse brings together data from multiple independent systems and standardizes it. Naming conventions, formats, and measurements are aligned so that information appears consistent and reduces duplication. For example, if the same item is labeled differently in separate systems, the DWH unifies it under one consistent term.

Key Functions of a Data Warehouse:

A DWH acts as a central storage hub, managed by an organization or service provider that maintains and safeguards the stored data. It helps reduce storage and backup costs and preserves detailed transactional information at varying levels of granularity. This supports different data warehousing and analytical strategies.

Key functions include:

Data consolidations

Collecting information from all relevant sources, cleansing it, and storing it in one place.

Data cleaning

Ensuring the accuracy and consistency of data by validating and correcting issues.

Data integration

Merging data from multiple systems and presenting it as a unified view to users.

Data extraction

Retrieving data from organizational sources so it can be processed or analyzed.

Data transformation

Converting data into a format that is meaningful and ready for analysis.

Data loading

Placing processed data into the warehouse or another storage platform.

Refreshing

Updating existing data so the warehouse remains current.

Important: Data cleaning and transformation are essential steps for delivering high-quality information and improving the outcomes of data mining and analytical activities.

 Do the course


 

Comments

Post a Comment

Popular posts from this blog

Delete vs Truncate in MySQL and MS SQL Server

-
Delete vs Truncate in MySQL and MS SQL Server DELETE DELETE is a DML command. The DELETE statement is executed using a row lock; each row in the table is locked for deletion. We can specify filters in where clause It deletes specified data if a "where" condition exists. Delete activates a trigger because the operations are logged individually. Slower than truncate because it keeps logs. Rollback is possible. TRUNCATE TRUNCATE is a DDL command. TRUNCATE TABLE always locks the table and page but not each row. Cannot use the WHERE condition. It removes all the data. TRUNCATE TABLE cannot activate a trigger because the operation does not log individual row deletions. Faster performance-wise, because it doesn't keep any logs. Rollback is possible. DELETE and TRUNCATE both can be rolled back when used with TRANSACTION (TRUNCATE can be rolled back in SQL Server, but not in MySQL ). if there is a PK with auto increment, truncate will reset the counter Learn SQL with us at PCWorks...
Read more

What Is SQLite?

-
Image
  What Is SQLite? SQLite is a C-language library designed to implement a compact, high-speed, self-contained, and robust SQL database engine . It stands as the most widely employed database engine globally, integral to the operating systems of virtually all mobile phones and the majority of computers. Additionally, it is packaged within numerous everyday applications. The SQLite file format boasts stability, cross-platform compatibility, and backward compatibility. Developers commit to maintaining this stability until the year 2050. SQLite database files serve as prevalent containers for the exchange of rich content across systems and as a long-term archival format for data . The active usage of SQLite databases exceeds a staggering 1 trillion (1e12) instances [5]. It is noteworthy that the SQLite source code is in the public domain, making it freely accessible for use by anyone, without restrictions on purpose. Learn SQLite with us at PCWorkshops.     ...
Read more

SQL Project Ideas

-
Image
SQL Project Ideas Have you recently attended a data analytics or similar interview, and they asked  how you could prove your skills? Here are some ideas for databases to create and upload to GitHub to showcase your skills if you are looking to change jobs. :
Read more