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Category: Powershell

Notes On Automating Automatic Indexing

Published 2018-05-01 by Kevin Feasel

Grant Fritchey shares with us some of his findings with automatic indexing on Azure SQL Database:

What you’ll notice is that several of the queries are filtering on the FirstName column. There’s no good index there. If you look at the execution plans for those queries you’ll also note the Missing Index suggestion. That suggestion is a necessary part of the automatic indexing. Yeah, missing indexes. I know. They’re not always accurate. It’s just a suggestion. Blah, blah, blah. I hear you.

The magic is not supplied by missing indexes. The magic is supplied by lots of data. Microsoft can take advantage of three things. Yes, missing index suggestions is first. Then, they can use the query metrics gathered in Query Store to see the behavior of your queries over time. Finally, they can use machine learning algorithms to determine if indexes will be helpful and measure how helpful they’ve been if one gets added. It’s great stuff. Go and read on it.

Click through for more notes, as well as a Powershell script you can use to replicate his findings.

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Using Powershell To Find Linked Server References

Published 2018-04-30 by Kevin Feasel

Drew Furgiuele shows us how we can use the sqlserver Powershell module to find linked server references in code:

SQL Search is doing exactly what it’s designed to do here: it’s finding every object that matches that string, HumanResources. It’s unfortunate that it also happens to be the name of my linked server and a schema in my database, but such is life, right? Its returning every object it hits a match on, which includes a bunch of views, plus one of those views actually contains my linked server reference.

I love SQL Search

Let me be clear: I’m not here to gang up on the fine folks at Redgate. This tool is beautiful and I love it. Otherwise, how else could we quickly search for objects in our databases? The alterative would be either querying system views for object definitions or using cursors to call sp_helptext over and over, and then trying to do pattern matching. Same as what SQL Search does.

There’s no easy way to sort this wheat from chaff, is there? This might be a starting point; let’s narrow down the search the objects we might need to look at. Then, we’ll manually script each one out, one at a time. That sounds an awful lot like a manual process. “If only there was a way to automate this checking”, he asked, sarcastically.

Click through for a very interesting cmdlet.

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Powershell: Validating Parameters Using Private Functions

Published 2018-04-27 by Kevin Feasel

Mike Robbins shows how to split out validation from your primary function within Powershell:

They responded by asking if it was possible to move the custom message that Throw returns to the private function. At first, I didn’t think this would be possible, but decided to try the code to make an accurate determination instead of just assuming it wasn’t possible.

I’ve now learned something else which makes the whole process of moving the validation from the ValidateScript block to a private function much more user friendly which is what I think the person who asked the question was trying to accomplish.

If you have several parameters with somewhat complex validation logic, this makes maintenance a lot easier.

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Running dbachecks In Parallel

Published 2018-04-27 by Kevin Feasel

Caludio Silva shows how you can run multiple instances of dbachecks concurrently:

Imagine that I want to check for databases in Full Recovery Model on the production environment and I want to start (in parallel) a new check for the development environment where I want to check for Simple Recovery Model if this setting is not changed in the correct time frame, we can end checking for Full Recovery Model on the development environment where we want the Simple Recovery Model.

The first time I tried to run tests for some environments in parallel, that had the need to change some configs, I didn’t realise about this detail so I ended up with much more failed tests than the expected! The bell rang when the majority of the failed tests were from a specific test…the one I had changed the value.

Read the whole thing before you start running Task.Parallel or even running multiple copies of dbachecks in separate Powershell windows.

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Automating Data Importation With dbatools

Published 2018-04-24 by Kevin Feasel

Bob Pusateri shows how to keep a dataset up to date using Powershell and dbatools:

Now for the magic – let’s load some data! The dbatools command that does all the heavy lifting here is called Import-DbaCsvToSql. It loads CSV files into a SQL Server table quickly and easily. As an added bonus, the entire import is within a transaction, so if an error occurs everything gets rolled back. I like to specify my tables and datatypes ahead of time, but if you want to load into a table that doesn’t exist yet, this script will create a table and do its best to guess the appropriate datatype. To use, simply point it at a CSV file and a SQL Server instance, database, and (optionally) a table. It will take care of the rest.

It’s a nice post covering one more method of automating data loads without a major amount of orchestration.

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Type Information Change In Export-CSV Cmdlet

Published 2018-04-23 by Kevin Feasel

Max Trinidad notes that a default parameter in the Export-Csv cmdlet has flipped between Powershell on Windows and Powershell Core 6:

For a long time, in Windows PowerShell, we had to add the parameter “-NoTypeInformation“, so the “#TYPE …” line on the first row of the *CSV would not be included.

So, in Windows PowerShell executing the command without the “-NoTypeInformation” parameter, will produce the following result:

Now, using the same command in PowerShell Core without the “-NoTypeInformation” parameter, will produce a different result:

This is a better default, but I think it’s going to burn some people who have scripts pre-built expecting to clear out that first line.

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Creating Azure VMs Using Powershell: Laying The Groundwork

Published 2018-04-23 by Kevin Feasel

Robert Cain has part one of a two-part series on creating VMs in Azure using Powershell:

Creating a virtual machine is great, but it won’t be of much use unless it can communicate outside of itself. That’s where virtual networking comes in. To setup a virtual network, often abbreviated vnet, you need to accomplish three things. First is the creation of the virtual network itself. After the network is created, you need to define a security group for it. In essence, the security group defines a firewall. In the process of creating it, the PSAzure module automatically creates firewall rules that allow HTTP and RDP (Remote Desktop Protocol) traffic through the firewall. There are functions in PSAzure to create security groups at a lower level, allowing one to create alternate rules. This example will demonstrate the most common options.

The final step is to create a virtual NIC, or Network Interface Card. The NIC will form the bridge between the virtual network and the virtual machine, much like a physical network card allows a physical computer to connect to a real network. First off, a few variables are assigned. These will hold names for the security group, network and subnet names. The network addresses for the main network and subnet are also placed into into variables. Finally, a name is assigned to the NIC.

Check it out, especially if you build a lot of VMs in Azure.

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Running The SQL Server Features Discovery Report

Published 2018-04-19 by Kevin Feasel

Dave Mason shows us how to run the SQL Server features discovery report via command prompt and PowerShell:

I don’t need to validate SQL Server installations on a regular basis. When the need arises, my preference is to run the SQL Server features discovery report. Further, I prefer to run it from the command line. After looking up command line parameters one too many times, I decided to script it out.

It turns out the script commands are a little more complicated than I realized: there is a different setup.exe file for each version of SQL Server installed. I ended up making two script versions: a DOS batch file with hard-coded paths, and a PowerShell script that’s more robust. Check them out and let me know what you think. (Keep scrolling down for a report sample image.)

I’m not sure I’ve ever run that report, but now I know how to do it from Powershell.

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Synchronizing User Logins Across SQL Server Instances

Published 2018-04-18 by Kevin Feasel

Hamish Watson shows how easy it is to synchronize SQL authenticated logins using dbatools:

When building new servers the most important thing after restoring and securing the database is syncing up the users. This is especially important for Availability Groups as SQL Authenticated users required the SIDS to be the same.

In the past I had some very long winded code that would do the sync – it was a mixture of TSQL and PowerShell. It worked but you know – it was cumbersome.

Read on to see how life gets easier with dbatools.

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