Tickets. Each one helps make the solutions we support more feature complete, bigger, faster, and fixed-er. This month’s invitation from Brent asks us to describe one of the last tickets which was closed to give an insight into our day to day. As an introduction: this is a response from a Development DBA who is relatively new into a […]
Blocking in SQL Server will reduce throughput. Excessive blocking can be cause bottlenecks on our environments so helping to mitigate it. Here we’re going back to basics to look at how it happens and how having effective indexes can reduce it. Blocking We’ll start off with an example of blocking. Here’s our customer table and […]
The DISTINCT clause in a query can help us quickly remove duplicates from our results. Sometimes it can be beneficial to stop and ask why. Why do we need to use the clause, why are we receiving duplicates from our data? I see this typically due to a JOIN being used where we don’t really want all of those results. This could […]
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 […]
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 