A Fine Slice Of SQL Server
Rob Farley like a syntax change:
This was fine, but it did start to become a little cumbersome.
Enter SQL Server 2022. Not only do we get the ability to ignore nulls now, making it easy to get the last non-null value from a list, but we also get a WINDOW clause – part of the SELECT query itself, dropping in between the HAVING clause and the ORDER BY clause, allowing us to predefine those OVER clause segments.
Read on for the full scope of Rob’s thoughts.
Comments closedKevin Kline musters the troops:
I received a great collection of blog posts in response to T-SQL Tuesday 153 which I kicked off on Tuesday, August 2nd – asking you to write about a conference or event that had a significant event on their life. As one of the small handful of people who attended every PASS Summit from its founding through the pandemic lockdown, I’ve witnessed so many transformational experiences firsthand.
Human beings are social creatures and though we as IT pros like to focus on hard technology skills first and foremost, I think we can all admit that having a great social experience at a conference like the PASS Summit in North America, SQLBits in the UK, or Data Platform Summit in India is at least as important as the technical learning.
Read on for a summary of several posts.
Comments closedIt’s time to do the round up of this month’s T-SQL Tuesday entries. It was great to see so many people responding, including at least one new participant. I think there are a lot of kindred spirits here, as in we’ve all felt each other’s pain. (I know that I personally can relate to way too many of these things.) And I truly enjoyed reading everyone’s post.
Click through for the full rundown.
Comments closedJosh Darnell provides timeless advice:
As Deborah’s invite post suggests, this is a “that one time at that client” story. I was working at a consulting firm, and we had written an app for a particular client. Part of this application’s workflow involved users uploading images alongside some other information. These were not particularly large images in the grand scheme of things – they were taken by a microscope, and were a few kilobytes each, maybe.
However, this app had been in use for a long time. And as you might have guessed from the title of this post, each of these images was stored in a single table in the database that backed this application
Yeah, that’ll be a problem… Read on for some recommendations on how to avoid the issue. One thing I would add is FileTable, which came out in SQL Server 2012. In that case, the files are actually stored on disk but are queryable via T-SQL. It introduces its own set of problems but I do have some fond feelings about having used FileTable in the past.
Comments closedShane O’Neill gets on the soapbox:
Part of why I’m ranting about database-ubiquitousness SQL instead of ORMs is that I’ve also witnessed SQL code that has to work everywhere
I’m going to call this SQL “DUh SQL” from now on since I only have so many vowels on my keyboard and shouldn’t waste them re-writing the word “ubiquitousness”
Them: “Nope, we can’t use DATEFROMPARTS; it’s not available in other databases! Yeah, we use GETDATE() everywhere; what’s your point? WHAT!?!”
I strongly agree with this. Lowest common denominator SQL just means your code is likely to perform poorly in all environments. Even if you know you need to support multiple platforms, it’s better to get the most out of each and have whichever data access layer implementation you inject figure out the details of how to do it.
Comments closedKenneth Fisher strikes a chord:
If your POC does not follow your companies best practices and standards then it is not a valid POC.
There are way to many settings that will change it’s performance, cause security issues, etc. On top of that, almost every POC I’ve ever seen ends up becoming the test environment if not the actual production environment. So all of those little compromises end up in your actual, non POC environment because it’s way too much work to fix them now. You should have said something when we set this up.
To use one of my favorite lines, “Short answer: yes with an if; long answer: no with a but.”
Before I get to the answer, I do want to differentiate between a proof of concept and a pilot. The idea of a proof of concept is to see if I can make this thing work. Can I get these two processes to talk to each other? Can I build a website which accepts user input and displays something? Can I get this idea from my head into code? Can I process 500,000 records per second using our existing hardware? One important thing about a proof of concept is that it always has the possibility of failure. “No” is a valid answer here based on the conditions. By contrast, a pilot is a starter for the full project. You might work with one business unit instead of all of them, migrate a small amount of traffic to the new system, or only handle data from a single branch office. Also, you want that answer as fast as is reasonable so that your business decision-makers can make business decisions on that information. By contrast, when we do a pilot, we already know the answer is yes; we just need to build it out and answer the technical details along the way.
Returning to the line above: Yes, I agree with Kenneth if your company lacks the discipline to differentiate between proofs of concept and pilots (and that’s not as denigrating a remark as it sounds…though it’s somewhat denigrating). No, do not follow the same practices for a proof of concept that you would for a full product, but you need to ensure that code gets destroyed and you start over with new code which does follow those practices.
2 CommentsJames McGillivray offers us an important piece of advice:
I cannot stress this enough. If people are consuming your data in multiple places, the data needs to come from the same data model. That can be an Enterprise Data Warehouse, a Data Mart, a Power BI Model, or any other data source, but at some point you need to be able to track the data back to a single place. If you don’t do this, you will spend THE REST OF YOUR DAYS explaining the differences between the data models to business and customers, and reconciling the differences over and over again.
Read on to learn why this is so important.
Comments closedGlenn Berry gives us two rants for the price of one:
This is rant #1. Even though I have an unusual fascination with computer hardware, I am still somewhat taken aback when I encounter DBAs who have absolutely no idea what type of hardware they are using. I’ll sometimes ask a DBA “What processor does your most important database server have?”, and I often get a “deer in headlights” look in response. Then a mumbled response, “I’m not sure, maybe a Xeon?”.
Read on for this rant, as well as the origin story of Glenn’s outstanding SQL Server Diagnostic Information Queries.
Comments closedTracy Boggiano opens a can of worms:
So, what to rant about? Should your managers have access to your SQL Server instances? It depends. You say on what. Well, just one thing. What type of manager do you have?
Read on for Tracy’s thoughts on the matter. Speaking as a manager, I tend to agree. If you don’t know what you’re doing, better not to have the ability to mess things up. I can think of oddball scenarios where you might still want the manager to have (at least theoretical) access to a system, primarily as a backstop in case the line staff get locked out or someone gets hit by the lottery bus and you suddenly need to bring in a new employee. That’s more of “break glass in case of emergency” access, though.
Comments closedI once worked for an Entity Framework SaaS company that was having horrific T-SQL performance issues. We put out a major release one weekend and spent the subsequent week buried in horrible performance hell. Because all T-SQL code was generated from Entity Framework (stored procedures were banned by a development exec prior to me joining the company), there were no easy fixes that could be implemented (and a Production release typically took 12 – 36 hours, I wish I was joking).
The manager of infrastructure had heard about SQL Server’s missing index recommendations:
Yep, it ends about as poorly as you’d expect.
Comments closed