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 […]
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 […]
Recently we looked at single threaded concurrency in SQL Server for workloads which only need a single core to execute. We saw how they ran at the same time with the queries effectively being round-robined on the CPU. This time out I wanted to look at how the concurrency looks when we’re working with multithreaded workloads. Setting […]
The question for today: if we have three queries – one which takes 1 second to run, one which takes 2 seconds to run, and one which takes 3 seconds to run – how long will it take to return data for the first and last query if they all start at the same time? […]
When building data solutions we’ll be handling sets of data which may need to be imported, transformed, aggregated or exported amongst other things. With more complex solutions can come a need to share this data between different areas of the process. Last week we looked at being able to share individual values within a session and […]
A few weeks back we looked at options for storing multiple boolean flag values in a table. One of the options we considered was the use of a Bit Mask where we packed multiple flags into a single field. When we have individual fields within a table, using and manipulating those is straightforward. However when we’ve got […]
Whilst we have front-end code which requires faster response times, there are also times we build code with the purpose of running for extended periods of time. Examples of this could be maintenance routine, or custom built queuing mechanisms. The way in which we design longer running processes like this can be key when it […]
Andy Brownsword 