Andy Leonard : Database Testing

Revisiting Test-Driven Database Development

andyleonard — Tue, 07 Aug 2012 09:00:00 GMT

I received an email from a database professional asking about re-executable T-SQL. I directed the developer to my series at SQL Server Central on Test-Driven Development: An Example of Test-Driven Development An Example of Test-Driven Development, Part...(read more)

Quick Database Connectivity Testing

andyleonard — Fri, 26 Aug 2011 16:00:00 GMT

Introduction Ever find yourself needing to test connectivity, but you’re on a machine with no client tools? It happens to me occasionally. Here’s one trick to help: UDL files Right-click on the Windows Desktop, hover over New, and click Text Document:...(read more)

An Example of Test-Driven Development, Part 5 republished!

andyleonard — Fri, 26 Nov 2010 17:49:00 GMT

My friends at SQLServerCentral.com have republished the fifth article in my TDD series: An Example of Test-Driven Development, Part 5 ! :{>...(read more)

Article: An Example of Test-Driven Development, Part 4

andyleonard — Fri, 19 Nov 2010 17:00:00 GMT

SQL Server Central has graciously republished my article An Example of Test-Driven Development, Part 4 today! I also wrote the SSC Question of the Day about an interesting quirk when executing encrypted and non-encrypted SSIS packages. :{>...(read more)

Database Development Infrastructure

andyleonard — Thu, 18 Nov 2010 16:00:00 GMT

Introduction I am often asked about database development best practices. The foundation of best practices is simple: Create a copy of the production environment to be used for quality testing. Business Case "It doubles the infrastructure costs!" Really?...(read more)

Article: An Example of Test-Driven Development, Part 3

andyleonard — Fri, 12 Nov 2010 12:00:00 GMT

Christy and I are enjoying our last full day in Seattle today. We miss the kids terribly and look forward to the last party or two this evening, followed by the long redeye home. Today, SQLServerCentral republished another article in my Test-Driven Database...(read more)

Article: An Example of Test-Driven Development, Part 2

andyleonard — Fri, 05 Nov 2010 11:00:00 GMT

Today, SQLServerCentral republished another article in my Test-Driven Database Development series: An Example of Test-Driven Database Development , Part 2 . (Thanks SSC!) :{>...(read more)

Database Security Testing

andyleonard — Tue, 02 Nov 2010 11:00:00 GMT

Introduction Tony Davis ( Blog ) wrote an interesting post ( SA no more! - ha!) about users, developers, and especially third-party applications requiring sysadmin or sa login access. Tony makes an excellent point: "Ultimately, the business needs the...(read more)

Presenting to SQLLunch 14 Jul 2010!

andyleonard — Fri, 09 Jul 2010 11:00:00 GMT

I am excited and honored to do my very first presentation at SQLLunch.com ! My talk is 14 Jul 2010 at 12:30 EDT. The topic is Transact-SQL Development and Deployment . :{>...(read more)

Speaking in Reston VA Monday 22 Jun!

andyleonard — Fri, 19 Jun 2009 16:48:00 GMT

I just learned I am presenting to NoVaSQL (Northern Virginia SQL Server User Group) Monday! Woo hoo! I'm looking forward to it - I always have a good time at NoVaSQL. I am honored and excited to present Database Development and Application Lifecycle Management...(read more)

Database Edition and You - Some Cool Changes

andyleonard — Tue, 07 Oct 2008 18:15:00 GMT

Greg Low mentioned the new licensing model for Database Edition is his post on the topic a few days ago. What does this mean for you?

Here's my take: Now that Database Edition is included (free as in beer) with Developer Edition, application developers can take advantage of some of the awesome features built into Database Edition. What are some of those awesome features? I'm glad you asked.

Unit and Database Tests - you can create database tests (and custom test conditions). Stored Procedure unit tests can be created by right-clicking the procedure and selecting "Create Unit Test".
Data Generation - you can populate a test database with gibberish. This is a great test for your database as users will likely store lots of gibberish in your database once the application goes live. Did I type that out loud? Bad me. Seriously, using live data for development and test purposes is at best a bad idea; at worst against the law. Data Generation incorporates foreign key relationships into the matrix, so related data and relationships are also simulated. (This assumes the use of foreign keys in database design...).

There's more, but this should be enough to prompt you to head over to MSDN and download Database Edition.

:{> Andy

Database Edition Now Does DB2!

andyleonard — Mon, 16 Jun 2008 16:20:00 GMT

Tech Ed 2008 included some major announcements for database development folks. One of the biggees was this - and announcement that Database Edition is going to support DB2 development!

Gert and the team have been working hard to expand the underlying architecture and functionality of Database Edition (making it extrememly difficult for this one author I know in Farmville to keep up... I'm not complaining!). Rearchitecting Data Dude to utilize a provider-based model was no small task, but the team at Microsoft has been able to pull it off - way to go team!

These changes affect a lot of how Database Edition currently works. We were given a preview at the MVP Summit in April. The work is impressive, but the ability and agility provided by the new architecture is even more so.

You will see a ton of changes with the release of Visual Studio Team System 2008 Database Edition GDR. You can currently download the June CTP here.

:{> Andy

Twitter Woes

andyleonard — Fri, 30 May 2008 13:42:00 GMT

"My name is Andy Leonard. I tweet."

"Hi Andy, we love you."

It's true, I am a bona fide Twitter-holic. If you use the service you may have noticed disruptions lately. Frank La Vigne (recently married - congratulations Frank!) blogged about it. The Twitter developers are blogging about it. And they have raised the ire of Mr. Scoble, who posted his feelings on the matter at FriendFeed - a competing service (if "competing" applies here...).

From the Twitter Dev blog:

The events that hit our system the hardest are generally when "popular" users - that is, users with large numbers of followers and people they're following - perform a number of actions in rapid succession. This usually results in a number of big queries that pile up in our database(s). Not running scripts to follow thousands of users at a time would be a help, but that's behavior we have to limit on our side.

The Twitter Dev comments have been interpreted by some as complaining about user load. This is not good for Twitter and they should take immediate steps to manage the buzz before this goes any farther.

I jokingly tell clients sometimes the problem with their application or database performance is a combination of their data and their clients. I only do this in person and after reaching a comfortable comfort level with the client, and even then it's sarcasm that I carefully throw out. Why? It's the technological equivalent of saying the word "bomb" while waiting in the security line at the airport - within earshot of the good people of the TSA.

In other words, it's a really dumb thing to say.

Let's look at why: First, Twitter is demonstrating that they made a mistake in architecture. I don't know what that mistake is, but it's obvious to everyone using or attempting to use the platform that an error has occurred. It's not the HTTP 500 error I saw last night or the on-again-off-again link to older tweets. It goes beyond that back to the design.

Part of the problem can be stated thus: "Twitter did not know we were going to grow so fast." Another way to say that is "Twitter doesn't scale."

As a database professional in the data warehousing field, I feel Twitter's pain.

We are often pressured to "just make it go!" - deliver something now and fix it later. And oh the temptation is strong, the logic sounds sound, the song so sweet... "you can circle around later and fix it" they say. When you hear these words and are so tempted you can be certain of one and only one thing: the person saying this to you is lying. Malice may or may not be present - they may simply be repeating what they heard or they may be utterly ignorant, but they speak not the truth.

Second - although I could be wrong about this - I would wager good money that Twitter doesn't need a DBA. I've seen / heard / experienced this before. They have a talented team of application developers who have built large applications in the past and never once paid a database professional. Look at the money they've saved! </sarcasm>

Why does this happen? Experienced database professionals slow down project development. We get in the way. We muck about with stress tests and bulky architectures and referential integrity and schemas and the like. Who needs us? We're an unnecessary expense.

Or are we?

From the quote above, the bottleneck is occuring in the database. It's those pesky queries. And the users causing them to be executed. It's <insert-your-favorite-excuse-here> - everyone and everything, except the designers and architects who built a non-scaling solution.

My lovely bride Christy has this saying: "Good judgment comes from experience, and experience comes from bad judgment." My hope is Twitter will discontinue offering excuses and blaming users, and instead fix the (apparently database-scaling-related) problem.

If this comes across as harsh, that is not my intention. I have been there and done that myself. These are learning experiences and growth opportunities. Hopefully Twitter will enjoy the fruits of this learning and growth in the future.

For now, I've created a FriendFeed account. Let's see how they scale...

:{> Andy

Transcript of .Net Rocks Show on Database Testing in CoDe!

andyleonard — Sun, 20 Apr 2008 23:21:00 GMT

The transcript of the first few minutes of the .Net Rocks Show on Database Testing is in the new issue of CoDe Magazine!

Coincidentally, I was presenting on the topic of Database Testing in Roanoke, VA a couple weeks back when the Roanoke Valley .Net User Group received their copies of CoDe Magazine. Robin Edwards (aka Geekette) asked at the end of the meeting "How come you didn't tell us you're in CoDe?" I had no idea.

But it's really cool!

Speaking of CoDe Magazine, I got to meet Markus Egger at the MVP Summit last week - cool guy!

:{> Andy

Speaking in Roanoke Va Thursday

andyleonard — Tue, 01 Apr 2008 21:01:00 GMT

I'll be presenting Testing the Database to the Roanoke Valley .Net User Group Thursday 3 April 2008. If you read this blog and you're in the area, stop by and introduce yourself!

:{> Andy