Press "Enter" to skip to content

Month: June 2017

Performance Comparison: Comparing Column Differences

Published 2017-06-23 by Kevin Feasel

Shane O’Neill has a column difference showdown:

The original post for this topic garnered the attention of a commenter who pointed out that the same result could be gathered using a couple of UNION ALLs and those lovely set-based EXCEPT and INTERSECT keywords.

I personally think that both options work and whatever you feel comfortable with, use that.

It did play on my mind though of what the performance differences would be…what would the difference in STATISTICS IO, TIME be? What would the difference in Execution Plans be? Would there even be any difference between the two or are they the same thing? How come it’s always the things I tell myself not to forget that I end up forgetting?

This may not be the most important thing to test, but it does show you a technique.

Comments closed

Using dbatools To Back Up SQL Logins

Published 2017-06-23 by Kevin Feasel

Claudio Silva has a post showing how to use the Export-SqlLogin cmdlet to back up SQL Server logins on all databases on a set of instances:

With a database restore, the users are within a database and if their SID matches the SQL Login you are ready to go. But with the logins it is a different story!
If you have to reinstall the engine because your master database backup is corrupt or someone hs changed the login password and you want to put it back or even – maybe the most common scenario – you want to keep track of the login permissions you need to have them saved somewhere.

Imagine that you have to re-create a login and give all the permissions that it has, imagine that this login has multiple roles on different databases. Did you know that beforehand? Do you keep track of it? How much time would take to gather all that information from the application owner? How much time will you have to spend resolving all the permission issues until everything is running smoothly? How many tickets will need to be raised? How many users will this be affecting?

Read on for Claudio’s easy solution.

Comments closed

SSMS Keyboard Tricks

Published 2017-06-23 by Kevin Feasel

Andrew Kelly has a few tricks up his sleeve when it comes to Management Studio shortcuts:

I was giving an internal talk on SSMS productivity trips and there were a few that I believe are seldom used but can be a real time or keystroke saver that I would like to mention. To the best of my knowledge these will work in any version of SSMS from at least 14.0 onward and likely earlier but I can’t verify older versions at this time. Since these are basically Visual Studio shortcuts they also work in Visual Studio and SSDT to the best of my knowledge. The first is the ability to select text in a vertical fashion as shown in the examples below. Before we get to how to do that I know your first question is why would you want to do that. Well I will leave all the possibilities up to you since everyone has slightly different techniques and circumstances. However I am confident that after seeing a few examples it will spark interest in many of you and you will immediately think of times when this will help you code more efficiently.

Read on for five tips.

Comments closed

Business Use Cases For Temporal Tables

Published 2017-06-22 by Kevin Feasel

Bert Wagner walks through some of the business cases for using temporal tables:

I know this query seems lame — it’s just a SELECT FROM statement. There are no FOR SYSTEM TIME clauses, WHERE statements, and no other interesting T-SQL features.

But that’s the point! Have you ever had to get the “current” rows out of a table that is keeping track of all transactions? I’m sure it involved some GROUP BY statements, some window functions, and more than a few cups of coffee.

Temporal tables automatically manage your transaction history, providing the most current records in one table (dbo.CarInventory) and all of the historical transactions in another (dbo.CarInventoryHistory). No need for complicated queries.

Temporal tables definitely have their uses.  At present, those uses are primarily around versioned fact data.

Comments closed

Using Python In SQL Server 2017

Published 2017-06-22 by Kevin Feasel

Prashanth Jayaram walks through installing SQL Server Machine Learning Services and running Python external scripts in SQL Server 2017:

Python supports a limited number of data types in comparison to SQL Server. As a result, whenever you use data from SQL Server in Python scripts, the data might be implicitly converted to a type compatible with Python. However, often an exact conversion cannot be performed automatically, and an error is returned. This table lists the implicit conversions that are provided. Other data types are not supported.

This article will get you started, and from there, the wide world of Anaconda awaits you.

Comments closed

Openrowset On Linux

Published 2017-06-22 by Kevin Feasel

Steve Jones shows how to use the OPENROWSET command to bulk load data into SQL Server on Linux:

I wanted to import the million song dataset in SQL Server on Linux. There’s a github repo that has the SQL to allow you to use this with the graph database features. However, it’s built for Windows.

Linux is a slightly different beast. Once I started down this path, I had memories of working on SunOS in college, messing with permissions and moving files.

I run Ubuntu in VMWare, so I first downloaded the files to my Documents folder. That’s pretty easy. However, once there, the mssql user can’t read them. Rather than mess with permissions for my home, I decided to move these to a location where the mssql user could read them.

Much of the post is about file permissions.  This is because SQL on Linux is SQL on Windows, and that’s a glorious thing.

Comments closed

Persisting Containerized Data

Published 2017-06-22 by Kevin Feasel

Andrew Pruski has started a series on persisting data in Docker containers.  He starts off the series with an easy method of keeping data around after you delete the container:

Normally when I work with SQL instances within containers I treat them as throw-away objects. Any modifications that I make to the databases within will be lost when I drop the container.

However, what if I want to persist the data that I have in my containers? Well, there are options to do just that. One method is to mount a directory from the host into a container.

Full documentation can be found here but I’ll run through an example step-by-step here.

Statefulness has been a tough nut to crack for containers.  I’m interested in seeing what Andrew comes up with.

Comments closed

The Importance Of A Test Environment

Published 2017-06-22 by Kevin Feasel

Randolph West explains why it’s important to have a test environment separate from your development and production environments:

Some companies I’ve worked with have different forms of testing environments, including QA (Quality Assurance), IAT (Internal Acceptance Testing), and UAT (User Acceptance Testing). What they are called doesn’t matter, so long as they exist.

In a typical IT deployment, whether using Waterfall, Agile, or other development methodologies of the month, it pays to have a basic development → test → production deployment path.

Randolph explains it in some detail but one of the big benefits for me is that you can make sure that deployment process works before deployment time.  Knowing that your checked-in scripts won’t break the deployment (because they didn’t break the CI build and release) makes the release process a lot less stressful.

Comments closed

Automatic Processing Of Azure Analysis Services Models

Published 2017-06-22 by Kevin Feasel

Dustin Ryan shows how to use Azure Functions to refresh Azure Analysis Services models:

Download the latest client libraries for Analysis Services. This needs to be done on your local machine so you can then copy these files to your Azure Function App.

After you’ve downloaded the client libraries, the DLLs can be found in C:\Program Files (x86)\Microsoft SQL Server\140\SDK\Assemblies. The two files you need are:

C:\Program Files (x86)\Microsoft SQL Server\140\SDK\Assemblies\Microsoft.AnalysisServices.Core.DLL
C:\Program Files (x86)\Microsoft SQL Server\140\SDK\Assemblies\Microsoft.AnalysisServices.Tabular.DLL

This step is important because the documentation in Azure references the 130 assemblies, which will not work. You need the assemblies in 140 otherwise you’ll get errors.

Dustin walks through the whole process of setting up an Azure Function step by step.

Comments closed