A Fine Slice Of SQL Server
Patrick Gruenauer makes a remote connection:
With Powershell 7, we can enable and use SSH Remoting. Unlike WinRM, SSH is more popular because it is a more familiar technology and is also available on other platforms. In this post I will show you how to easily enable SSH on PowerShell 7 with a few lines of code.
Click through to see what you need to install on the machine and how to configure everything.
Comments closedChad Callihan embraces the power of AND:
Data can be inserted into one temp table from another a couple of ways. There is the INSERT INTO option and the SELECT INTO option.
Are you devoted to one option over the other? Maybe you’re used to one and never experimented with the other. Let’s test each and compare performance to find out which is more efficient.
Both of these are useful, though Chad does mention a performance improvement with SELECT INTO. I tend to prefer INSERT INTO for “structured” scenarios because it lets me define the shape of the output table. When I don’t care what the shape is—for example, when I just need some data one time to perform an analysis—then I prefer SELECT INTO for its simplicity.
Comments closedHasan Savran won’t settle for just one date:
GENERATE_SERIES function is introduced in SQL Server 2022 version. It is a simple function that generates a series of numbers within a given interval. It requires compatibility level 160.
The natural use for it is to generate a set of numbers, but as Hasan shows, you can easily turn that into a set of dates or dates and times.
Comments closedVishaal Kapoor, et al, take us through an example of pattern learning in Amazon SageMaker:
Pattern learning automatically analyzes your data and surfaces textual constraints that may apply to your dataset. For the example with phone numbers, pattern learning can analyze the data and identify that the vast majority of phone numbers follow the textual constraint
[1-9][0-9]{2}-[0-9][4]. It can also alert you that there are examples of invalid data so that you can exclude or correct them.In the following sections, we demonstrate how to use pattern learning in Data Wrangler using a fictional dataset of product categories and SKU (stock keeping unit) codes.
Read on for the scenario.
Comments closedIn databases, we often find columns that are stored in a hierarchy structure, not unlike a file path on your drive. For example, in the Microsoft Logs sample database the
Perftable stores its counter path this way:\\computername\Memory\Available MBytes.It would be helpful to have a way to easily break this path out into its individual parts. KQL provides us a way of doing this using the
splitfunction.
Check out examples of how you can perform splitting.
Comments closedBrendan Tierney wants rowcounts:
A little warning before using these queries. They may or may not give the true accurate number of records in the tables. These examples illustrate extracting the number of records from the data dictionaries of the databases. This is dependent on background processes being run to gather this information. These background processes run from time to time, anything from a few minutes to many tens of minutes. So, these results are good indication of the number of records in each table.
Click through for examples in Oracle, MySQL, Postgres, SQL Server, and Snowflake. Though the SQL Server one does need a GROUP BY clause because it’s a sum of the partitions’ rows.
Comments closedYochanan Rachamim explains why you might see different information between tools:
When using Performance Dashboard on Azure SQL Managed Instance you may find that percent of CPU usage is different (lower) than reported by Azure Portal for your Managed Instance.
You may wonder which is the correct value.
Click through for the answer.
Comments closedMarco Russo and Alberto Ferrari ask who you believe, them or your lying eyes:
When looking at a report, it is natural to double-check the numbers produced. The simplest and most intuitive way is to verify whether the total equals the sum of individual rows. This behavior is extremely natural and mostly effective. Nonetheless, the total is the sum of rows only for additive measures, which are measures that are naturally computed as a sum.
When working with business intelligence solutions, sooner or later a developer will author a calculation that is non-additive. At that point, the total can no longer be computed by summing the rows for a very good reason: it would be inaccurate. When users complain about the fact that the rows do not sum up, seasoned BI developers offer a rational explanation of the reasons why the number are not summed: this process often provides a better understanding of how values are computed. Choosing the easy way out of introducing additivity in a naturally non-additive calculation means losing the opportunity to generate accurate calculations, and relying on inaccurate values.
Read on for examples and how to understand how to deal with non-additive or semi-additive features.
Comments closedGrant Fritchey provides some tips:
One thing you see a lot is that people, for whatever reason, will absolutely not simply state what the actual problem is. You’ll get stuff like “What SQL Server internal behavior prevents dynamically naming local variables?” And you’re left scratching your head, why on earth would someone want to dynamically name local variables? Only to find out, after lots of comment & discussion, they thought that you needed to rename variables when changing values.
When you get stuck, take a moment to describe the problem, but aim for the root of the problem, not peripheries. “I want to do X. I’m doing X. It looks like this. The results are this when they should be that. What am I doing wrong?” That’s the “magic” formula.
Grant provides several helpful tips for increasing the likelihood that someone will help you find the right answer.
I want to note two quick things here, though. The first is that, quite often, people don’t even know what they intend to ask. In the cited bit above, this quite often comes from basic confusion cascading into specific “I’m stuck here” questions. This leads to foundational misunderstandings between people and frustrates the question-and-answer process.
The second thing I’d note is, be clear in your writing. The biggest tip I have here is to make sure your sentences and ideas flow. In other words, within a paragraph or section, try to keep thoughts related to the key topic and avoid asides or rambling. The reason for this is that your inner monologue can make sense of a variety of asides, but a reader without access to your thoughts will struggle to follow along. Furthermore, it is common to add bits and pieces to a half-finished post, fleshing out details. Before posting, make sure that it makes reading sense. Quite often, people will write a post and then fill in additional details before submission. A common result of this is that you might add some information intended to clarify a point which you actually introduce later in the post.
Comments closedDave Shook announces a new course:
Properly designing your events and event streams is essential for any event-driven architecture. Precisely how you design and implement them will significantly affect not only what you can do today, but what you can do tomorrow. For such a critical part of any data infrastructure, most event streaming tutorials gloss over event design.
In the new course on Confluent Developer, events and event streams are put front and center. We’re going to look at the dimensions of event and event stream design and how to apply them to real-world problems. But dimensions and theory are nothing without best practices, so we are also going to take a look at these to help keep you clear of pitfalls and set you up for success. This course also includes hands-on exercises, during which you will work through use cases related to the different dimensions of event design and event streaming.
Click through to learn more about what’s in the course and to check it out–it is free, after all.
Comments closed