In building a database, typically we want a well normalized design. However there are cases for considering options for denormalization in complex systems. Timothy Claason gives you some thoughts on the subject.  Read more...

The process of properly architecting databases via bridge tables  Read more...

I have a requirement to implement a custom security scheme where roles and the user's place in the organization hierarchy are used to determine which customers a user can access. In particular the requirements are that a sales person can only access their customers and any other role can access any customer in their level of the organization hierarchy and below. We have a simple hierarchy that is made up of regions and offices. Can you provide us with an example of how to do this?  Read more...

Do your system contain a time bomb in the code? David Poole looks at some potential situations where you might be experiencing performance issues and delves into why.  Read more...

What are the benefits of Effective Dating and what problems does it solve?  Read more...

This article discusses different ways to query multiple databases and shows a simple, web-based tool I've created and routinely use for those SaaS-style web applications I work on that use separate databases to store different customer data. Read on to learn more!   Read more...

The second article in our series about designing multi-tenant applications identifies three distinct approaches for creating data architectures.  Read more...

The key to working with null values properly is to accommodate them consistently. Learn a few tricks that will help you do just that.   Read more...

Perhaps we need to protect more data, according to Steve Jones. With the ability to identify most people with 10 digits of information, Steve Jones asks you to really think about what you need to store.  Read more...

Perhaps we need to protect more data, according to Steve Jones. With the ability to identify most people with 10 digits of information, Steve Jones asks you to really think about what you need to store.  Read more...

Perhaps we need to protect more data, according to Steve Jones. With the ability to identify most people with 10 digits of information, Steve Jones asks you to really think about what you need to store.  Read more...

Perhaps we need to protect more data, according to Steve Jones. With the ability to identify most people with 10 digits of information, Steve Jones asks you to really think about what you need to store.  Read more...

This script can be used to create new tables in a database from a parent table that is normalised using this script. a detailed explanation can be found in the comments.   Read more...

Full/partial schema refreshes across environments are a regular requirement in databases. This article builds on a previous article, providing scripts to disable and re-enable foreign key constraints on all of the tables in a schema.  Read more...

You've probably all noticed a change since SQL Server 2000 with respect to objects: formerly DB.ObjectOwner.Object ,  Read more...

A forum posting, from someone who wanted a better solution to the common problem of handling global settings in a database, leads Joe Celko into a fascinating discussion of the ramifications of the various solutions.  Read more...

In this next installment of his series on TDD, MVP Andy Leonard continues the development of his database.  Read more...

Follow the rules to ensure granular data, flexibility and a future-proofed information resource. Break the rules and you'll confuse users and run into data warehousing brick walls.  Read more...

When discussing the normalisation process, it is always the First Normal Form that causes the most grief and confusion. Anith Sen takes up the challenge to explain, in simple terms, exactly what the First Normal Form really is, and why it is so important for Database Design. Along the way, he dispels some of the myths that have grown up around 1NF.  Read more...

Too many authors in the field of relational theory have neglected the concept of Cardinal Reciprocity. This can cause a number of subtle problems with database design in terms of its derivability, redundancy, and consistency. . Increasingly, this little-understood aspect of relational theory, that emphasises the cardinality of the attributes of tuples in a relation and the reciprocity with isomorphic foreign key restraints, is becoming a hot forum topic.  Read more...