A candidate key is an important concept in database normalization. Read on to find out what a candidate key is and how to check if a set of attributes is a candidate key. The candidate key, also simply called a key, is an important part of database design. It is the theoretical foundation for technical concepts like primary and alternate (unique) keys. Every database designer should be aware of how to identify candidate keys and how to choose the right one for their table.
Do you know what a closure of a set of attributes is? Do you know how to find it? This knowledge is essential for database normalization. In this article, learn what a closure of a set of attributes is and how to find it with real-world examples. Finding the closure of a set of attributes is an important topic for relational databases. The closure of a set of attributes is taught in every university database class.
What is a one-to-one relationship in data modeling? How do you implement this relationship in a database? The examples in this article will answer these questions. There are three types of relationships between entities (tables) in data modeling: One-to-many relationships (also denoted as 1:M). Many-to-many relationships (M:N). One-to-one relationships (1:1). The most common type of relationship is a one-to-many relationship, where a record in one entity can be referenced by multiple records in another entity.
Database Normalization in Simple English Have you heard of 2NF, 3NF, and BCNF? Do you know what the database normal forms mean? In this article, you will learn database normalization in simple English. With real-world examples, you will better understand what normal forms are, why there are different types, and why we need them. Database courses typically teach database normalization and normal forms abstractly. Functional dependencies and normalization problems are defined using letters (e.
Normalization in Relational Databases: First Normal Form (1NF), Second Normal Form (2NF), and Third Normal Form (3NF)
What is database normalization? What are the different normal forms, and what do they do? Find out in this article. Normalization in relational databases is a design process that minimizes data redundancy and avoids update anomalies. Basically, you want each piece of information to be stored exactly once; if the information changes, you only have to update it in one place. The theory of normal forms gives rigorous meaning to these informal concepts.
How difficult is it to program a user login function for an application? Novice developers think it’s very easy. Experienced developers know better: it is the most sensitive process in your application. Errors in login screens can lead to serious security issues. In this article we take a look at how to store authentication data in your database. The most common way to authenticate users nowadays is with user name and password.
The Turing Award is an annual prize given by the Association for Computing Machinery (ACM) “for contributions of a technical nature made to the computing community.” It is sometimes referred to as the “Nobel Prize” in Computing. Currently, the prize is 1 million dollars with funding provided by Google. The 2014 Turing Award – announced just three weeks ago on March 25, 2015 – was given to Michael Stonebraker, who earned the award for “fundamental contributions to database systems, which are one of the critical applications of computers today.
Back in the day when I was still a PhD student, I helped to organize two scientific conferences that took place in my institute. If you’ve ever been to a big 1000-person developers’ conference, scientific conferences are nothing like them. They usually have around 100 participants; a 300-person conference is considered big. Scientific conferences are organized by the faculty of the university where the event takes place, with some help from interested students or PhD students.
I recently realized that our database modeling library could use a few more advanced titles. So I headed over to Amazon to see what they had on offer. There are plenty of introductory books for beginners that tell you how to normalize data, and introduce you to indexes, but what about something for the professional, grown-up database modeler? Here are 5 of the best database modeling books I found (listed in no particular order) that go beyond the basics and come highly recommended by Amazon reviewers.
Anyone who had to schedule an intercontinental phone call knows that there is no such thing as a simple time called now. What you should rather think about is a time comprised of here and now. The Earth rotates around its own axis. When it’s solar noon (the sun is at its highest position) in one place, it’s already past noon in places to the east and it’s still before noon in places to the west.