Data Engineer and Nerd
Performance issues in SSIS packages can be tough to track down. You know something is off but trawling through pages of SSIS reporting and the validation noise is frustrating. Adding your own logging is a nice idea but not feasible at scale. An alternative? Querying internal tables within the SSIS database is a quicker way […]
When creating SQL Agent jobs to execute SSIS packages we can choose the level of logging to be captured. Different settings are more beneficial under the right circumstances so it’s important to understand the differences to make the right decision. These settings control the internal logging done by SSIS. This is out of the box […]
Code is an ever moving target. Version control and documentation only go so far, if they even exist. Sometimes all you have is the code in front of you. This is why I always start stored procedures with a header. Here’s a template as a starter: Name seems redundant as we have the proc name below […]
Uploading into a SharePoint list from an Excel document is straightforward to do, but populating multi-value fields isn’t so easy. This can be solved using Power Automate and I wanted to share how easily it can be done (⚠️ Warning: lots of images ahead). In brief, we’ll be doing the following: Let’s take an order […]
One particular performance issue with SSIS data flows can fly under the radar – spilling to disk. This isn’t clearly visible through regular debugging or execution so can go unnoticed. And it hurts. Paging to disk is bad for performance. Disks are much slower to access than memory, so we want to keep our data […]
Sometimes you want to segment records. It may be splitting a customer base for marketing purposes, or segmenting a user base for a new feature. Good segmentation makes clean divisions in the data. In this post we’ll see a way to achieve that with a great deal of help from Window Functions. This post was […]
We’ve recently looked at how caching can improve performance and I wanted to show how we can eek even more performance out of caches by using a custom approach I’ll term Selective Caching. I’ll note here that there’s a potential gotcha with this approach which we’ll get to before the end of the post! Scenario Let’s say […]
Last week we looked at using a cache to improve lookup performance. We saw how a cache improves performance by being able to reuse reference data repeatedly. That used a regular cache but it’s not the only option available to us. In this post we’re going to look at the File Cache option which can achieve […]
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 […]
Andy Brownsword 