The scale of change in the insurance and financial markets is such that there is little time for the application or database developer to sit back and work out ways of improving the delivery process. Over time, however, it is possible to improve the process so that individual heroics are required less and less as release and deployment become more managed and predictable. It can be messy and error-prone at times but the long-term benefits make the struggle worthwhile.… Read more
Relational databases go out of their way to execute SQL, however bad the crimes against Codd and relational theory within the query. The 'conditional join', can be executed but at great cost. As always, it is much better to sit back and restate the problem in a set-based way. The results can be rewarding.… Read more
What's the best way of providing self-service business intelligence (BI) to data that is held in on-premise SQL Server? Not, it seems, Power BI 2.0 the hosted cloud service, but Power BI 2.0 Desktop. If moving your database to Azure isn't an option, Power BI 2.0 desktop could still bring smiles to the faces of your BI hotshots.… Read more
For an experienced database developer, the idea of doing non-breaking database deployments while the database is still online holds respect but only a little fear. If your test procedures are good, you attend to the detail, and the application interfaces are properly managed, it can be achieved. Ed Elliott explains some of the issues to tackle.… Read more
SQLXML isn't exactly new technology, but like the even more venerable BCP, it remains the quickest and most reliable way of heaving large quantities of data into SQL Server databases. SQLXML is very versatile, and once set up is wonderfully reliable ETL system, but isn't trivial to learn. Adam Aspin comes to the rescue with a simple guide.… Read more
Database programmers are often caught in the paradox of wanting to implement business rules and complex functionality in one place only, but being concerned by the performance hit of having generic functions or procedures that have a wide range of parameters and outputs. Alex Kuznetsov, in an article taken from his book 'Defensive Database Programming with SQL Server', shows how DRY principles can be put in practice with constraints, stored procedures, triggers, UDFs and indexes.… Read more
Once you're clear about what data the developers and testers need to be able to be effective, you have several alternatives approaches to providing them exactly the data that will give you rock solid database tests that will allow deployments with far less risk. Tim goes through some practical demos to show you how you can automatically keep your testing environments up to date, and thereby ship more robust databases.… Read more
Michael Fal is a huge advocate of automation and many ways it can improve the lives of developers and DBAs alike, but you can't just automate all your problems away. The real challenge is breaking down barriers and having developers and DBAs functioning smoothly together. You may have heard of DevOps, and so Mike explores what the buzz might mean for database administrators.… Read more
One of the shocks that a developer can get when starting to program in T-SQL is that there is no simple way of generating documentation for routines, structures and interfaces, in the way that Javadocs or Doxygen provides. To embed the documentation in the source is so obvious and easy that it is a wrench to be without this facility. Phil Factor suggests a solution. … Read more
R and SQL Server are a match made in heaven. You don't need anything special to get started beyond the basic instructions. Once you have jumped the hurdle of reliably and quickly transferring data between R and SQL Server you are ready to discover the power of a relational database when when combined with statistical computing and graphics.… Read more
Refactoring code won't cause performance problems, right? This was the assumption when Chris Hurley and his team went out to improve some legacy code. They decided to separate the database access from business logic and standardise on Entity Framework, but when it came time to test the code using real-world workloads, unexpected performance issues appeared. Chris recounts how they discovered, investigated, and resolved these issues using ANTS Performance Profiler. … Read more
Microsoft 'Always On' technology does not support distributed or cross-database transactions. Why not? Grahaeme Ross shows how to investigate cross-database transactions to understand the problem in more detail, and concludes that a Cross-Database transaction can cause loss of data integrity in the commit phase of the two-phase commit… Read more
Access-control within the database is important for the security of data, but it should be simple to implement. It is easy to become overwhelmed by the jargon of principals, securables, owners, schemas, roles, users and permissions, but beneath the apparent complexity, there is a schema-based system that, in combination with database roles and ownership-chaining, provides a relatively simple working solution.… Read more
One of the most certain ways of going wrong with any relational database is to get data conversion wrong. Implicit data conversion is a good feature for the expert but can cause a lot of trouble to the unwary. These boil down to seven ways of failing to get data conversion right. Rob Sheldon explains and gives sage advice on how to avoid the problems… Read more
Refactoring a database object can often cause unexpected behavior in the code that accesses that object. In this article, adapted from his excellent book, Defensive Database Programming with SQL Server, Alex Kuznetsov discusses several techniques that will harden your code, so that it will not break, or behave unpredictably, as a result such changes.… Read more
When you're developing database applications, it pays to check for index scans in the SQL Server query plan cache. Once you've identified the queries, what next? Dennes Torres gives some preliminary guidelines on how to find out why these index scans are being chosen for these queries and how to make the queries run faster and more efficiently.… Read more
Database Design is one of those tasks where you have to carefully get all the major aspects right. If you mess-up just one of these, it can all go horribly wrong. So what are these aspects that can ruin database design, and how can you get them right? Robert Sheldon explains.… Read more
Behaviour Driven Development is not always clearly understood, and the term is particularly unfamiliar in database circles. Seb Rose introduces us to the fundamentals of BDD, and make some suggestions for how it might be relevant to database development.… Read more
Where applications are evolved by gradually molding them to a growing understanding of the business domain, this presents great challenges to database development. If databases are designed too loosely, and initial errors are allowed to fester, the results become harder and harder to refactor until eventually they constitute a database time bomb. Thomas LeBlanc describes how to avoid a few basic, but very common, database time bombs. … Read more
A database must be able to maintain and enforce the business rules and relationships in data in order to maintain the data model. It does this through referential constraints. They aren't complex, but are powerful, especially with the means to attach DRI actions to them. Joe Celko explains all, and pines for the ANSI CREATE ASSERTION statement… Read more
