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Curated SQL Posts

Tracking T-SQL Code Progress

Published 2018-02-12 by Kevin Feasel

Louis Davidson has a couple of ways of tracking progress and success of T-SQL code:

For a process that runs for 10 seconds, this is no problem at all. But when you are doing 100s of loops, and they take time, you don’t want to wait. Eventually, data will start spurting out, but not immediately. We want immediately, even if it isn’t the optimum way.

The PRINT statement won’t output immediately, but its cousin, good old RAISERROR, does. Using a severity of 10 for the message, the message will be output just like a PRINT message. Then, adding WITH NOWAIT to the RAISERROR, the messages will no longer be queued for output, and will be returned immediately.

Both of the techniques Louis shares are useful for keeping track of progress in code.  I’d expect that as tooling gets more sophisticated with respect to live execution plans, we might eventually get to the point where there’s an overall expected progress indicator, something which would be quite useful when three levels of management are standing at your desk waiting for something to finish.

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Quick Update Stats Job

Published 2018-02-12 by Kevin Feasel

Amy Herold has a Powershell script to generate a SQL Agent job which updates statistics for defined tables:

In an effort to rule out whether or not statistics are definitely a factor, I want to UPDATE STATS on all the tables in my query, and at a specific time – sometime the day before we expect our slowdown to occur. I also want to be able to easily see how long the process ran and the duration of the update for each table. I could write all this to a table, and maybe I will do this later, but viewing this from job history is what I want right now – it is easy to look at and easy for everyone else to find and see as well.

Creating a job with multiple steps can sometimes be a bit painful and tedious, if the job is going to have A LOT of steps. With PowerShell, a server name and a database, I can dynamically create this job.

One of many reasons to have at least a little bit of Powershell knowledge if you are a SQL Server DBA.

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Annotations And ObjectTags In Biml

Published 2018-02-12 by Kevin Feasel

Cathrine Wilhelmsen explains how to use Annotations and ObjectTags to store metadata in Biml:

There are two types of annotations in the Biml language. The first type is SSIS Annotations. An SSIS annotation is a comment inside your SSIS package that is visible on the design surface. This is what most SSIS developers think of when they hear the word “annotation”.

The second type, and the type covered in this blog post, is Biml Annotations. Biml annotations are more than just comments inside a package. They can be used to store additional string metadata on any Biml object, and can also be used in auto-generated documentation.

There are four types of Biml annotations: CodeComment, Documentation, Description, and Tag. You can read more about them in the official AnnotationType documentation.

I know I’ve underused Annotations in my Biml work, so this was good to read.

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Digging Into The In-Memory Columnstore Location

Published 2018-02-12 by Kevin Feasel

Niko Neugebauer does some investigation into where, exactly, memory-optimized columnstore data goes:

This is a rather simple blog post that is dedicated to the theme of the In-Memory Columnstore Indexes location. This has been a constant topic of discussion over a long period of time, even during the public events – and there is a need to clear out this topic.

I have assumed that the In-Memory Columnstore structures (Segments, Dictionaries, …) are located in the In-Memory, but there have been voices that I greatly respect, pointing that actually the Columnstore Object Pool is the exact location of any Columnstore structures, and there is nothing better than to take this feature for a ride and see what the SQL Server engine is actually doing.

Niko shows off a couple of useful DMVs along the way, too.

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Analyzing Spatial Data With Cosmos DB

Published 2018-02-09 by Kevin Feasel

Ben Jarvis shows how to query spatial data from Cosmos DB:

The above code connects to Cosmos DB and retrieves the details for the base airfield that was specified, it then calculates the range of the aircraft in meters by multiplying the endurance (in hours) by the true airspeed in knots (nautical miles per hour) and then multiplying that my 1852 (number of meters in a nautical mile). A Linq query is then run against Cosmos DB using the built-in spatial functions to find airfields within the specified distance. The result is then converted into a JSON array that can be understood by the Google Maps API that is being used on the client side.

The client side uses the Google Maps API to plot the airfields on a map, giving us a view like the one below when given a base airfield of Blackbushe (EGLK), a true airspeed of 100kts and an endurance of 4.5 hours

Click through for .NET code to load and analyze the data.

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Faceted ggplot2

Published 2018-02-09 by Kevin Feasel

I have another post in my ggplot2 series, this time covering facets:

Notice that we create a graph per continent by setting facets = ~continent.  The tilde there is important—it’s a one-sided formula.  You could also write c("continent") if that’s clearer to you.

I also set the number of columns, guaranteeing that we see no more than 3 columns of grids. I could alternatively set nrow, which would guarantee we see no more than a certain number of rows.

There are a couple other interesting features in facet_wrap. First, we can set scales = "free" if we want to draw each grid as if the others did not exist. By default, we use a scale of “fixed” to ensure that everything plots on the same scale. I prefer that for this exercise because it lets us more easily see those continental clusters.

Facets let you compare multiple graphs quickly.  They’re great for fast comparison, but as I show in the post, you can distort the way the data looks by lining it up horizontally or vertically.

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Exploring MSSQL-CLI

Published 2018-02-09 by Kevin Feasel

Drew Furgiuele hates the pernicious effect of graphical user interfaces and wants to return to nobler times:

Okay, fine, who’s this really for?

Anyone, I suppose, but in reality? If you’re stuck on a remote system that only allows terminal logins, this is a super handy tool to use. If you’re used to text-based editors, like Emacs, Nano, or even vi or vim, you’ll feel right at home in here. You can type in commands and then run queries. There’s even multi-line support for more complex stuff. There’s another side to this too: if you’re the kind of DBA that gets really mad if someone installs management studio on a server, then this might be a solution: it’s got a very small installation footprint, and you don’t get a full UI experience so unless you know all the big T-SQL commands for heavy administration (like for, say, dealing with an availability group or adding permissions, or taking or restoring backups), you won’t get much use out of it. But in a pinch, on a server, in a crisis where you can’t tell if SQL is up and serving queries? It just might work out well for you.

Read the whole thing for an enlightening Q&A session, although the question-asker is kind of a jerk to the answerer.

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When Nanoseconds Count

Published 2018-02-09 by Kevin Feasel

Joe Chang thinks about single-socket servers:

There is a mechanism by which we can significantly influence memory latency in a multi-processor (socket) server system, that being memory locality. But few applications actually make use of the NUMA APIs in this regard. Some hypervisors like VMware allow VMs to be created with cores and memory from the same node. What may not be appreciated, however, is that even local node memory on a multi-processor system has significantly higher latency than memory access on a (physical) single-socket system.

That the single processor system has low memory latency was interesting but non-actionable bit of knowledge, until recently. The widespread practice in IT world was to have the 2-way system as the baseline standard. Single socket systems were relegated to small business and turnkey solutions. From long ago to a few years ago, there was a valid basis for this, though the reasons changed over the years. When multi-core processors began to appear, the 2-way became much more powerful than necessary for many secondary applications. But this was also the time virtualization became popular, which gave new reason to continue the 2-way as baseline practice.

Joe points out that for a highly-used transactional system, the lower memory latency might make a single-socket server perform better than a multi-socket server.

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Options For Deploying Power BI Reports

Published 2018-02-09 by Kevin Feasel

Eugene Meidinger covers the various deployment options for Power BI:

Even worse, Power BI is rapidly being iterated on. This is great for users, but a challenge for people trying to keep up with the technology. One year ago the following deployment options modes didn’t exist.

  1. Sharing individual reports (Jan 2018)
  2. “Apps” (May 2017)
  3. SharePoint Embedding (Feb 2017)
  4. Power BI Premium (May 2017)
  5. Power BI Report Server (June 2017)
  6. Power BI Embedded V2 (May 2017)

It can be a real challenge to keep up. I think that a lot of the dust has settled when it comes to deployment options. I don’t see them adding a lot of new methods. But I expect there to be many small tweaks as time goes on. In fact I had to make two changes to my slides this morning because they announced changes yesterday!

In contrast, I expect another six to be added to this list in the coming three months.  Because it’s Power BI and the only rule behind Power BI is that there must be more.

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More Keyboard Shortcuts

Published 2018-02-09 by Kevin Feasel

Andy Mallon has a great shortcuts cheat sheet for SQL Server Management Studio and SQL Operations Studio:

Nearly two year ago, I first published my Shortcuts cheat sheet. Since then, thousands of people have downloaded it. I’ll be the first to admit that I didn’t expect it to be as much of a hit as it has been. When I give my one-hour talk in person, I bring card stock handouts of my cheat sheets, too. I also ask people for their favorite shortcuts, and I’ve learned some great new hidden gems.

I’ve been working on some updates, and the updated version is ready to go. I’ve added a bunch more shortcuts, and even added shortcuts for SQL Operations Studio. It’s two pages now, for double the fun!

That’s great stuff.  Learning these keyboard shortcuts will provide a nice marginal benefit to your productivity.

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