Lookup transformations provide us a way to access related values from another source, such as retrieving surrogate keys in data warehousing. When we need multiple lookups to the same reference data we can improve performance through the use of a Cache. If we consider data warehousing, a prime example of this would be an order […]
Implicit conversion happens in SQL Server when the engine detects a mismatch in data types and automatically converts from one type to another. This can be helpful as it makes different types interchangeable and is generally transparent to the client, but it can come with issues. Usually the downside from implicit conversion is seen through […]
When running queries, reviewing execution plans, or diving into Query Store it’s not uncommon to see missing index recommendations, particularly for more complex queries. But are they any good? There are many factors when considering an index. However if you’re a situation where these missing index recommendations are enticing, I wanted to cover 3 key areas you […]
When using data flows in SSIS packages we want the flow to be fast and fluid. Improving performance of the flows will vary in different packages, but one element can consistently help – tuning memory utilisation. In this post we’ll look at tuning the memory utilisation by altering the number of rows passing through the flow concurrently. […]
When looking to increase performance for a database it can be the smaller and faster queries which can be improved easier and more effectively than their slower counterparts. We can be drawn to tuning long running and complex queries, but these can be a challenge due to their size and complexity. Sometimes though we can reclaim just […]
Having persisted with Windows 11’s context menu for long enough, it’s time to concede. I find it too restrictive and slows down the muscle memory. If you yearn for that touch of Windows 10 back in your life, read on. Reverting from the new style context menu should look something like this: But it isn’t. […]
Parameters in Paginated reports allow for us to tailor report contents based on user selected criteria. These were inherited from Reporting Services as a precursor to the slicers and filters in Power BI reports. Coming from a Reporting Services background I have a soft spot for pre-defined paginated reports. However these parameters can sometimes get […]
The UNION and UNION ALL operators allow us to combine results, but there’s no guarantee that each set of results uses the same data types. So what data types are returned? For the longest time I thought the data types from the first set of results were used for the final results. That’s not the case. Understanding how this […]
When restoring a database in different environments we may stumble across orphan users. This typically manifests through failed connections to the database. Here we’ll have a quick look at what the issue is and 3 ways to fix it. What are orphaned users When users are created in a database they’re mapped to the login […]
Window functions allow us to perform a function across a set of rows in a result set, rather than how we might typically group them. In SQL Server 2022 we have a new clause available for our queries which can help tidy up how these are defined. We’ll use the sample table from the introduction to […]
Andy Brownsword 