Data Engineer and Nerd
This month’s invitation from Reitse asks us to talk about learnings from abandoned or failed projects. This one will sit somewhere squarely between those two points. It was an opportunity to learn about scalability. Let’s set the scene. A point of sale system being rolled out across hundreds of physical locations. Transaction data collected each night to […]
In the previous post we looked at the functions TRY_CAST, TRY_CONVERT, and TRY_PARSE and how they compared. I wrapped up and said that my preference for new developments would be to use TRY_PARSE due to the tighter control which it provides us. As with everything in SQL Server however, there is no ‘best’ approach, it depends. I therefore wanted […]
In the previous post we looked at how ISNUMERIC and TRY_CAST work and why we may want to utilise the latter when building validation for our data. When SQL Server 2012 rolled around it wasn’t only TRY_CAST which was added, we also had TRY_CONVERT and TRY_PARSE introduced too. Here we’re going to look at how […]
Data validation is key when ingesting from external sources. As we can’t always be certain of data quality we inevitably find bad data which needs to be handled. Here I wanted to look at a couple of options for validating numeric data. Here’s the scenario – we’ve got data which may have been received via […]
This month’s invitation from Kay asks us to look back through the year and consider those who we are thankful for. Whilst I should be thanking those close to me for their ongoing support through a lot this year – the fact of it is that they aren’t the type of folks to be reading a blog about SQL […]
We’re on quite a roll with window functions these past few weeks. Last week we looked at the operators we’d see in execution plans when using a window function. This week I wanted to tackle one of the more troublesome ones specifically: the Sort operator. We know that sort operators are expensive in our queries. To use […]
After last week’s post I got to thinking that although we’ve looked at how to implement window functions, we haven’t peeked under the hood to see how they are executed. Then what do you know, Kevin has picked up my post to provide an alternative approach. He observed that whilst his approach was more straightforward it produced a more […]
We revisited window functions last week for T-SQL Tuesday. As we’re in that area there’s another example I thought was worth exploring. Can we group data whilst applying window functions in the same query? The problem For our example we’ll use the same sample data as last week. This contains sales values broken down by period, also […]
This month’s invitation from Steve asks us to about how window functions have made life easier for us. Before we get into that let’s have a brief recap of what window functions are for those who aren’t familiar. What are they? Window functions are like regular functions we’d use in a result set such as SUM() or MIN() but more […]
Our SQL Server environments are home to many workloads. In these situations one size doesn’t always fit all when it comes to configuration. Let’s take an example. On one hand we want small, high performance, transactional processing during the day. Through the evening this could change to larger, batch processing tasks. I’ve seen the configuration […]
Andy Brownsword 