Constraints and the Test-Driven Database

Bad data always seems to appear when, and where, one least expects it. Sam explains the great value of a defensive approach based on constraints to any team that is developing an application in which the data has to be exactly right, and where bad data could cause consequential severe financial damage. It is perhaps better seen as creating a test-driven database.

Table space usage 1

Prime Attributes

Yet Another SQL Strategy for Versioned Data

There is a popular design for a database that requires a built-in audit-trail of amendments and additions, where data is never deleted, but superseded by a later version. Whilst this is conceptually simple, it has always made reporting the latest version of data complicated. Alex Kuznetsov joins the debate on the best way of doing this with an example using an indexed view and the filtered index.

Implementing Queuing Mechanism

Implementing a queue table in SQL server

A Tale of Identifiers

Identifiers aren't locators, and they aren't pointers or links either. They are a logical concept in a relational database, and, unlike the more traditional methods of accessing data, don't derive from the way that data gets stored. Identifiers uniquely identify members of the set, and it should be possible to validate and verify them. Celko somehow involves watches and taxi cabs to illustrate the point.

Database Design Example: Curriculum Vitae

I’ve explained the database design process in a series of articles that you can find here. In this tutorial, I’ll put that information to good use and design a database from the start of the process to the finish. To keep this example to a single article, I’ll not repeat the information from those previous articles, so make sure you look those over before reading this one.

Table Design

Look-up Tables in SQL

Lookup tables can be a force for good in a relational database. Whereas the 'One True Lookup Table' remains a classic of bad database design, an auxiliary table that holds static data, and is used to lookup values, still has powerful magic. Joe Celko explains....

SQL Server: Natural Key Versus Surrogate Key

When designing a database to support applications you need to consider how you are going to handle primary keys. This article explores natural and surrogate keys, and discusses the pros and cons of each, allowing you to determine what makes the best sense in your environment when you are designing your databases.