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Category: Administration

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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Tracking Down Long-Running xp_cmdshell Processes

Published 2018-04-26 by Kevin Feasel

Thomas Rushton investigates what’s taking so long with an xp_cmdshell call:

I wanted to know what he was up to, but the sql_text field only gives “xp_cmdshell”, not anything useful that might help to identify what went wrong.

So we have to go to Taskmanager on the server. On the “Process Details” page, you can select which detail columns you want to see. We want to see the Command Line, as that’ll tell us if it’s some manually-launched batch job that’s failed or something else going wrong.

An alternative to using the Task Manager is to open ProcMon, part of the Sysinternals toolset.  It takes a bit of getting used to, but is quite powerful once you know its ins and outs.

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Running The Azure DTU Calculator On An Older Server

Published 2018-04-25 by Kevin Feasel

Jim Donahoe shows us how to get the Azure DTU calculator running on an older server without Powershell:

I recently had to do an analysis of a client’s database workload using the Azure DTU Calculator(DTU Calculator) and thought it might be interesting to share just how I did that.  I have run this tool numerous times on other clients via the PowerShell method and the Command Line method, however this client’s environment was: Windows Server 2008R2, and SQL Server 2008R2 SP3 and had to be done differently.

Now, from the DTU Calculator page itself, it tells you how the process works.  It essentially runs a perfmon trace for an hour with the following counters:

  • Processor – % Processor Time
  • Logical Disk – Disk Reads/sec
  • Logical Disk – Disk Writes/sec
  • Database – Log Bytes Flushed/sec

My client did not have PowerShell accessible for me to use unfortunately.  I normally prefer the PowerShell script, however in this case I had to use the Command Line Interface, they both return the same results.

Click through to see how Jim did it.

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Finding Database Files In The Wrong Folder

Published 2018-04-25 by Kevin Feasel

Matthew McGiffen has a script which shows which database log and data files are outside of the default folder for that instance:

One common issue that bugs me is where databases have been moved from one instance to another, usually through backup and restore, and the files haven’t been moved as part of the restore so they get recreated in the data\log folders for the old instance.

This has caused me various problems, e.g. working out which instance is hammering the disk or using up all the space.

Click through for the script.

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Copying Azure SQL Databases

Published 2018-04-25 by Kevin Feasel

Arun Sirpal noticed a problem when he tried to copy an Azure SQL Database:

Now, I was looking at the following code.

CREATE DATABASE CodeDBP1
  AS COPY OF CodeDB ( SERVICE_OBJECTIVE = 'P1' )  ;

You would think this is okay? I did, especially with the fact that it parsed and was executing. I was thinking a copy of the CodeDB database will be created as a premium P1 database regardless of what the source database service tier was. This  source database is 0.5GB in size under the basic tier and 40 minutes later the copy was still executing. It just didn’t seem right.

Click through for the solution.  If this is going to be normal behavior, I’d really like to see an error message.

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Reading SQL Server Error Logs

Published 2018-04-23 by Kevin Feasel

Jana Sattainathan has a procedure which makes it easier to read the error logs in SQL Server:

xp_ReadErrorLog has some limitations

  • Reads only the specified error log whose ArchiveNumber is specified
  • Shows only the rows with matching string (not adjacent context info rows)

The first bullet is obvious in that we cannot read ALL the logs to look for something more holistic and meaningful with all the information we have. This MSSQLTips post does describe a method to loop through.

Click through for Jana’s stored procedure code.

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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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Configuring Telegraf To Monitor Windows Servers

Published 2018-04-18 by Kevin Feasel

Tracy Boggiano continues her series on configuring Telegraf:

The solution for this is fairly simple now that you have setup Part 1 of this series.  You can download the Windows conf file for Telegraf from my presentation.  Below are the important pieces of the file. The main part of the OUTPUT PLUGINS being to place the data in the InfluxDB database. The data will be housed in the same database as our SQL performance metrics. Next, you can collect any Windows Performance Counters you want and group them into a “Measurement”. I’m using the dashboard that is on the Grafana website along with the performance metrics they have set up to be collected.

Click through for Tracy’s setup script to get an idea of which Perfmon counters she’s tracking.

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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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