Press "Enter" to skip to content

Curated SQL Posts

Callout Lines

Published 2019-05-09 by Kevin Feasel

Lisa Charlotte Rost shows different sorts of callout lines and how they can affect the way a person views your chart:

After Defne’s awesome monster Weekly Charts in the last 14 days (here’s number 1, here’s number 2), this weeks’ Weekly Chart keeps it small. Today we launched callout lines for our locator maps (they are lines connecting marker and label), and I wrote a few words about how to create them and when – so I will simply refer you to this announcement blog post and explain the importance of our new feature with this map:

In moderation, they can be quite useful for indicating and explaining important but subtle points you’d like to make.

Comments closed

Forcing Plans with Table Variables

Published 2019-05-09 by Kevin Feasel

Grant Fritchey takes us through an interesting scenario around Query Store:

This weekend I was in Stockholm in Sweden, talking Query Store and plan forcing with Steinar Anderson, when he mentioned the problems he had while forcing plans that had table variables in them.

Don’t panic. Of course you can force a plan with a table variable, most of the time. Steinar had a fairly focused problem. Before I go on to explain the issue, let me be really clear, Steinar figured out the issue all on his own. When he outlined the problem, I saw immediately what his conclusion was going to be. What’s spurring this blog post is that Steinar said he’d searched on the internet and no one had talked about the issue yet. So, let’s talk about it.

Read on for the problem as well as solution.

Comments closed

Learning About Big Data Clusters

Published 2019-05-09 by Kevin Feasel

Kevin Chant shares resources for getting started with SQL Server Big Data Clusters:

In a previous post I shared current SQL Server 2019 learning resources, which you can view in detail here.

However, SQL Server 2019 Big Data Clusters are very involved. So, I thought I better dedicate a whole post to further learning resources for it.

Because some people have different learning methods I have included references to both documents and videos in this post. In addition, I have created the below links in case somebody wants to go directly to a specific section.

Kevin’s put together quite a few useful links here.

Comments closed

T-SQL Tips Regarding Subqueries

Published 2019-05-09 by Kevin Feasel

Itzik Ben-Gan provides quality information on working with subqueries in SQL Server:

In this plan you see a Nested Loops (Left Semi Join) operator, with a scan of the clustered index on Customers as the outer input and a seek in the index on the customerid column in the Orders as the inner input. You also see an outer reference (correlated parameter) based on the custid column in Customers, and the seek predicate Orders.customerid = Customers.custid.

So why are you getting the plan in Figure 1 and not the one in Figure 2? If you haven’t figured it out yet, look closely at the definitions of both tables—specifically the column names—and at the column names used in the query. You will notice that the Customers table holds customer IDs in a column called custid, and that the Orders table holds customer IDs in a column called customerid. However, the code uses custid in both the outer and inner queries. 

Itzik covers three specific scenarios, all of which can cause trouble to database developers who haven’t been burned yet. And sometimes even those who have.

Comments closed

NT AUTHORITY\ANONYMOUS Error Editing Procedures

Published 2019-05-09 by Kevin Feasel

Kenneth Fisher takes us through a security issue:

If you have to deal with linked servers then you probably have or will run into the following error:

Login failed for user ‘NT AUTHORITY\ANONYMOUS LOGON’

But I’m not trying to use the linked server. I’m trying to create/alter a stored procedure.

Kenneth explains why you might get this even when you’re just editing a procedure and not directly hitting a linked server, as well as a few tips for fixing the issue.

Comments closed

Persisting SQL Server Databases on Kubernetes

Published 2019-05-09 by Kevin Feasel

Anthony Nocentino walks us through persistent volumes and Kubernetes:

One of the key principals of Kubernetes is the ephemerality of Pods. No Pod is every redeployed, a completely new Pod is created. If a Pod dies, for whatever reason, a new Pod is created in its place there is no continuity in the state of that Pod. The newly created Pod will go back to the initial state of the container image defined in the Pod’s spec. This is very valuable for stateless workloads, not so much for stateful workloads like SQL Server.

This means that for a stateful workload like SQL Server we need to store both configuration and data externally from the Pod to maintain state through the recreation of a Pod. Kubernetes give us constructs two constructs to do that, environment variables and Persistent Volumes. 

Read on for a good bit of background and a few scripts to help you get started.

Comments closed

Load Testing Databases

Published 2019-05-09 by Kevin Feasel

Ed Elliott shares some tips on load testing a database:

Testing database performance is hard and takes a great deal of work to probably not even do particularly well. Instead of thinking about how you can load test a database think about how you can drive the application.

For instance, if you have a web app then use JMeter to simulate load. If you have a “fat app”, then you might need to write some code to call specific workflows through the application.

Click through for good advice, particularly around what you should not do.

Comments closed

Syncing Google Calendar and Outlook with Microsoft Flow

Published 2019-05-08 by Kevin Feasel

Eugene Meidinger shows how to keep a couple of calendars in sync:

Back when I worked a normal job, I had two calendars: Office 365 for work and Google for home. Now that I work for myself, that’s a lot more complicated. Sometimes a customer will create an account for me in their network. Sometimes I’ll partner with other consultants and work as part of their team. And of course, I’ve got my own work email at eugene@sqlgene.com.

I need all of these calendars to consolidate to one place. My natural inclination and personal preference is to put it all into Google. Now, there are sync apps available, but this sort of problem is a perfect use case. A calendar event is created in outlook, a flow is triggered, and that information is transferred to Google.

I was just complaining about this yesterday and then I see the post this morning. I’m pleased though simultaneously concerned that Eugene has bugged my hotel room.

Comments closed

Automating Jupyter Notebooks

Published 2019-05-08 by Kevin Feasel

I have some early thoughts on automating Jupyter notebooks:

In the command above, I included the date of execution. That way, I can script this to run once a day, storing results in an HTML file in some directory. Then, I can compare results over time and see when issues popped up.

I can also parse the resultant HTML if need be. Note that this won’t be trivial: even though the output looks like a simple [1] "PROBLEM ALERT", there’s a more complicated HTML blob. 

At some point I’ll probably have follow-up thoughts on the topic. Probably.

Comments closed

Deploying SQL Server Containers to Azure with Terraform

Published 2019-05-08 by Kevin Feasel

Andrew Pruski has a post covering deployment of SQL Server containers to Azure using Terraform:

What this is going to do is create an Azure Container Instance Group with one container it in, running SQL Server 2019 CTP 2.5. It’ll be publicly exposed to the internet on port 1433 (I’ll cover fixing that in a future post) so we’ll get a public IP that we can use to connect to.

Notice that the location and resource_group_name are set using variables that retrieve the values of the resource group are going to create.

Cool! We are ready to go!

Fun stuff, and Andrew promises more.

Comments closed