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
The speed of a slow SQL Query can almost always be improved. In SQL Server, the query optimizer determines the best way of executing the query, based on the evidence it has. The same query can be executed in many different ways as the data size increases, new indexes become available, or as the data distribution changes. If the appropriate index doesn't exist or can't be used, then SQL Server shrugs and does the best it can. Tony Davis explains how to find out what a query needs to perform w… Read more
It is sometimes hard to keep up with Microsoft's direction in Business Intelligence. Over the years, we've been presented with so many ways of aggregating, processing, graphing, reporting and visualising data, that we felt it was time to take stock and present the Simple BI Timeline, and explain how BI has evolved over the years.… Read more
By reading performance counters from services such as SQL Server or Exchange, you can get a wealth of performance information. By automating the process of gathering and storing appropriate counters, you can routinely check a range of devices quickly using visual tools such as PerfMon. By then creating your own counters, you can add counter-based metrics to anything that can be measured programmatically, such as services, applications, processes such as ETL, or deployments. … Read more
NULLs in SQL are a mixed blessing. The Three-Valued Logic of SQL has its uses but can cause difficulties to anyone who assumes that NULL has a 'value'. It can make reports go horribly wrong in a number of alarming ways, as Robert Sheldon explains.… 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
One of the times that you need things to go right is when you are doing analysis and reporting. This is generally based on time and date. A sure-fire way of getting managers upset is to get the figures horribly wrong by messing up the way that you handle datetime values in SQL Server. In the interests of peace, harmony and a long career in BI, Robert Sheldon outlines some of the worst mistakes you can make when using SQL Server dates.… Read more
WMI (Windows Management Instrumentation) is the basic way of querying and changing basic information about any windows server, including SQL Server or Exchange Server. It provides a logical structure and representation of systems and services that are hosted on the server and is essential for anyone who is keen to automate routine monitoring and administration work via PowerShell, especially where many servers are involved in the task.… Read more
Percentiles give meaning to measurements by telling you the percentage of the population being measured who get higher or lower values. They are now easier to calculate in SQL, and are useful for reporting; but are the new analytic functions faster and more efficient than the older methods? Dwain Camps demonstrates, and investigates their relative performance performance.… Read more
SQL Server batch processes are usually run from SQL Agent in background. They can take significant time and resources, especially if they are ETL tasks. Quite often, the responsibility for creating these tasks belongs entirely to the developer. Dennes demonstrates that DBAs can advise and assist with this type of batch job by bringing their expertise to bear on the problem of reducing their impact on the working system to a minimum.… 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
It is no good doing some or most of the aspects of SQL Server security right. You have to get them all right, because any effective penetration of your security is likely to spell disaster. If you fail in any of the ways that Robert Sheldon lists and describes, then you can't assume that your data is secure, and things are likely to go horribly wrong.… 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
For users to get the information they need from mobile reports, we frequently have to tailor the way we design those reports to the characteristics of the target device. Adam Aspin demonstrates some of the ways that we can deliver easy-to-use Business Intelligence to tablets and smartphones using Reporting Services. … 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 designing an application, there is a temptation to build it to a super-scalable future-proof architecture, even when the immediate requirements can be met by a simple single-tier application that can exploit the pure power of IIS and SQL Server. Dino recounts the painful story of what happened when the gurus got their way.… Read more
