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Author: Kevin Feasel

Availability Groups Over Mirroring

Published 2015-12-21 by Kevin Feasel

Kendra Little explains why Always-On Availability Groups are better than database mirroring:

SQL Server Availability Groups are growing up. SQL Server 2016 adds more features and improvements, and these include options to run SQL Server in different domains, or without a domain.

That brings Availability Groups closer to feature parity with Database Mirroring in SQL Server 2016.

The recent improvements caused me to think about the ways Availability Groups are better than Database Mirroring that aren’t listed as “big features”. (By “big features” I mean having more than one replica, having multiple databases fail over in a group, having multiple failover partners in SQL Server 2016, readable secondaries, having a basic load balancing concept in SQL Server 2016.) I think there’s a few.

Thinking about this for a small business with just enough technical expertise to get by but no dedicated DBA, mirroring seemed like a better choice because there were fewer moving parts.  With 2016 and AG bugfixes, that might change the calculus.

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Using Extended Events For Login Tracking

Published 2015-12-21 by Kevin Feasel

Steve Jones shows us how to track logins with Extended Events:

I can select any number of fields for capture. You can see I’ve picked the client_hostname. I would also add the NT_Username and Username from the list. You could add more, but in this case, I’m more concerned with seeing who’s logged in.

I could add filters, but I choose not to. I click on Data Storage to determine where to store this data.

If you’re not already familiar with Extended Events, that grace period is slowly slipping away.  Profiler’s going away sometime, and it’ll be a rude shock for a lot of DBAs.  Don’t be one of those…

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Scrubbing Data

Published 2015-12-21 by Kevin Feasel

Tom Norman has a series going on scrubbing data before moving it to lower environments.

Part 1:

Have you ever heard, “but it works on my machine”? Is this because of data perfection in Development and QA or having specific failure conditions? Can you think of all the data scenarios that accompany Production data? What about performance? Why did the application fail? What happens if I add this index?

Here are the reasons I believe you should get a scrubbed version of your production database into your Development, QA and UAT environments.

Part 2:

All of us have Production database servers and hopefully you also have additional database servers for Development, QA and UAT. Some IT shops will also have a Continuous Integration server and maybe other servers. If you only have Production servers this needs to be addressed and is outside the scope of this post. In the locations where I have worked, we also have a Scrub server. The question is, when a script executes, do you know what environment the query is executing in? Most scripts will not care what environment the script executes in but other scripts could cause damage in a Production environment. For example, if the script is removing email addresses so you don’t spam your clients with automated email messages, you would not want the script to execute in a Production environment.

So how do you make your database server environmentally aware?

 

The concept of a dedicated scrub server is interesting; it’s not something I’ve thought about before.  I’m looking forward to seeing the rest of the series.

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Watch Those DAX Calculations

Published 2015-12-18 by Kevin Feasel

Chris Webb shows us a case in which Power BI Desktop’s DAX calculation might not be what you expect:

The difference here is that the Month Number and Month Name fields are both present – they have to be since the query has to sort by Month Number. In MDX the order of members on a hierarchy can be set inside the model; in a DAX query you can only sort using an ORDER BY clause and for that to work, the field you’re ordering by must be present in the query.

This kind of feels like an edge case, but if you run into it, it’s good to know that it’s not a bug.

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Data Analysis With R: Tutorials

Published 2015-12-18 by Kevin Feasel

Revolution Analytics has a series of tutorials using SQL Server R Services:

You may have heard that R and the big-data RevoScaleR package have been integrated with with SQL Server 2016 as SQL Server R Services. If you’ve been wanting to try out R with SQL Server but haven’t been sure where to start, a new MSDN tutorial will take you through all the steps of creating a predictive model: from obtaining data for analysis, to building a statistical model, to creating a stored prodedure to make predictions from the model. To work through the tutorial, you’ll need a suitable Windows server on which to install the SQL Server 2016 Community Technology Preview, and make sure you have SQL Server R Services installed. You’ll also need a separate Windows machine (say a desktop or laptop) where you’ll install Revolution R Open and Revolution R Enterprise. Most of the computations will be happening in SQL Server, though, so this “data science client machine” doesn’t need to be as powerful.

The tutorial is made up of five lessons, which together should take you about 90 minutes to run though. If you run into problems, each lesson includes troubleshooting tips at the end.

SQL Server R Services has the potential to be a great tool.  The standard V1 warning obviously applies, but I’m excited.

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Object Level Auto-Stats

Published 2015-12-18 by Kevin Feasel

Andy Mallon on auto-statistics:

I’m not going to say whether I think Auto Update Statistics should be on or off. Instead, I’m going to argue that there are definitely scenarios when you want to have this on AND there are scenarios where you want it turned off. Can you really have this both ways? Absolutely.

I’m going to say yes to auto-update unless you know the answer is no for an object.  But it’s nice to know that the fine-grained option is available.

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Power BI Analysis Of Quickbooks Data

Published 2015-12-18 by Kevin Feasel

Rob Collie shows how to use QQube to help with Quickbooks data analysis:

Our financials are the logical first place to start.  And our financials are in the hands of our accounting firm.  Specifically, they are stored in Quickbooks.

This, of course, poses a problem.  Because like ALL accounting and ERP systems, Quickbooks is primarily focused on being a great accounting system.  A system that collects, stores, organizes, and routes data.  Quickbooks is NOT an analytics tool.

And being an analytics (or BI or reporting, whatever you call it) tool is a full-time job.  ANY system whose job it is to collect/organize/route data will NEVER be sufficient for reporting and analysis.  NEVER.  I’m not kidding.  We should never expect different, and that’s not a “knock” on these vendors.  It’s just too many missions for any one company to execute.

This is a nice walkthrough of how you can apply visualization and analytics concepts, especially in a small business scenario.

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Who Alerts When The Alerts Are Down?

Published 2015-12-18 by Kevin Feasel

Chris Bell uses Powershell to alert us when the SQL Agent service goes down:

Now that we have our PS1 file that will send the email alert, but we need to have the job run when the service fails. To set this open up services and right click on the SQLServerAgent service you wish to add the failure alert to and select properties. Navigate to the Recovery tab and set one of the failure actions to “Run a Program” I tend to choose it as the first failure action as I like to look at why my service failed before I just restart it. You can attempt to restart first and then run the program on if it fails again by setting the second failure to run a program. The choice is yours!

Very cool.

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