Press "Enter" to skip to content

Month: June 2017

Restoring A BACPAC File

Published 2017-06-02 by Kevin Feasel

Steve Jones shows how to restore a database saved in .bacpac format:

I needed to get the WideWorldImporters sample database for a project and noticed that there was a BACPAC available. I downloaded it and needed to restore this as a database. At least, that’s what many people would think.

However, if you go to the restore dialog, and select Device and then pick your location, there’s no filter for a .bacpac. In fact, if you choose one, it won’t restore. You’ll get the “no backupset selected” error.

Read on for a step-by-step guide showing how to do this.

Comments closed

Automating Azure SQL DB Maintenance

Published 2017-06-02 by Kevin Feasel

Tim Radney shows several methods for performing automated Azure SQL Database maintenance, including runbooks:

Once you create your account, you can then start creating runbooks. You can do just about anything with the runbooks. There are numerous existing run books that you can browse through and modify for your own use, including provisioning, monitoring, life cycle management, and more.

You can create the runbooks offline, or using the Azure Portal, and they’re built using PowerShell. In this example, we will reuse the code from the PowerShell demo and also demonstrate how we can use the built in Azure Service scheduler to run our existing PowerShell code and not have to rely on an on-premises scheduler, task scheduler, or Azure VM to schedule a job.

Read the whole thing if you have Azure SQL Database instances in your environment.

Comments closed

Dimensional Design Tips

Published 2017-06-02 by Kevin Feasel

Koen Verbeeck provides some helpful hints when designing dimensions in SQL Server Analysis Services Multidimensional models:

Although traditional dimension modeling – as explained by Ralph Kimball – tries to avoid snowflaking, it might help the processing of larger dimensions. For example, suppose you have a large customer dimension with over 10 million members. One attribute is the customer country. Realistically, there should only be a bit over 200 countries, maximum. When SSAS processes the dimension, it sends SELECT DISTINCT commands to SQL Server. Such a query on top of a large dimension might take some time. However, if you would snowflake (aka normalize) the country attribute into another dimension, the SELECT DISTINCT will run much faster. Here, you need to trade-off performance against the simplicity of your design.

There are several good tips here.

Comments closed

Smarter Differential Backups

Published 2017-06-02 by Kevin Feasel

Dennes Torres shows us how we can use a new column in an old DMV to make our full vs differential backup processes smarter:

What are the possibilities with this new field ? We are now able to check how many extents have changed since last full backup and decide if a full backup is really needed or we can live with a differential backup, achieving smarter backup plans.

Change our full backup jobs to first check this field and decide if the backup will be full or differential can save space and maintenance time with databases that aren’t updated so often.

Read on to learn more about this new column, which will be available in SQL Server 2017.

Comments closed

Cross-Database Queries With Azure SQL DB

Published 2017-06-01 by Kevin Feasel

Dustin Ryan shows how to set up cross-database queries within Azure SQL Database:

2. Vertical queries (in preview): A vertical elastic query is a query that is executed across databases that contain different schemas and different data sets. An elastic query can be executed across any two Azure SQL Database instances. This is actually really easy to set up and that what this blog post is about! The diagram below represents a query being issued against tables that exist in separate Azure SQL Database instances that contain different schemas.

Read on to learn how to implement vertical elastic queries today.

Comments closed

Using Common Table Expressions To Drive Queries

Published 2017-06-01 by Kevin Feasel

Lukas Eder wants one result set which returns records using predicate B if and only if there were no records using predicate A:

We’ve seen that we can easily solve the original problem with SQL only: Select some data from a table using predicate A, and if we don’t find any data for predicate A, then try finding data using predicate B from the same table.

Oracle and PostgreSQL can both optimise away the unnecessary query 2 by inserting a “probe” in their execution plans that knows whether the query 2 needs to be executed or not. In Oracle, we’ve even seen a situation where the combined query outperforms two individual queries. SQL Server 2014 surprisingly does not have such an optimisation.

Interesting totally-not-a-comparison between the three database products.  There are some things I’d ideally like the SQL Server optimizer to do with common table expressions, but as Lukas notes, it doesn’t, so user beware.

Comments closed

Multi-Channel Attribution With R

Published 2017-06-01 by Kevin Feasel

Sergey Bryl walks through some of the difficulties of the multi-channel attribution solution he came up with before:

The main steps that we will review are the following:

  • splitting paths depending on purchases counts

  • replacing some channels/touch points

  • a unique channel/touchpoint case

  • consequent duplicated channels in the path and higher order Markov chains

  • paths that haven’t led to a conversion

  • customer journey duration

  • attributing revenue and costs comparisons

There’s a lot there, and I like the practical explanations of issues when dealing with a real business problem.

Comments closed

Kerberos Constrained Delegation On Power BI Report Server

Published 2017-06-01 by Kevin Feasel

Regis Baccaro shows how to set up constrained delegation when connecting Power BI Report Server to a SQL Server instance or Analysis Services cube:

In many demo cases, you will have an all-in-one server where you have installed Power BI Report Server, SSAS (tabular or multidimensional) and SQL Server. In those cases you don’t need any form for credentials delegation since the Report Server is on the same box than the data source.

But there are scenarios where you have a distributed environment like the one I have on my VMs demo domain and for jumping around servers and passing credentials around, you need to setup Kerberos Constrained Delegation. Furthermore you will need protocol transition for it to work in Power BI Report Server.

Read on for step-by-step instructions showing how to do this.

Comments closed

Troubleshooting Distributed Replay Errors

Published 2017-06-01 by Kevin Feasel

Jonathan Kehayias walks through some common Distributed Replay errors and how to solve them:

On the Distributed Replay Controller machine, permissions need to be set in Component Services to allow the Distributed Replay Client Service accounts Launch and Activate permissions remotely on the COM component. The service accounts also need to be in the Distributed COM Users group in Windows. So in Component Services, expand Computers > My Computer > DCOM Config > DReplayController and right-click and open the Properties for the COM Component.

A lot of this boils down to permissions, but the error messages are about as unhelpful as they get.

Comments closed

Building Newlines In SQL Scripts

Published 2017-06-01 by Kevin Feasel

Shane O’Neill engages in wacky newline misadventures:

GO is a special little guy. It’s not exactly T-SQL. It’s a way of telling the SQL Server Management Studio (SSMS) to send everything before it, from the beginning of the script or the preceding GO, to the SQL Server instance.

If you read the documents, the main point to take away is…

A Transact-SQL statement cannot occupy the same line as a GO command. However, the line can contain comments.

The problem turns out to be a little trickier than you’d first imagine.  Also, after reading this post, I think it’s lunchtime…

Comments closed