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Category: Testing

Using DBCC OPTIMIZER_WHATIF To Mimic Production Hardware

Published 2018-07-24 by Kevin Feasel

Max Vernon has a technique for mimicking production hardware layouts when testing queries in development:

Attempting to debug production performance problems in your development environment can be problematic in many ways, leading to a frustrating troubleshooting experience. One very common situation is the resources on the development environment are substantially less robust than on the production system; for instance prod has 128 GB of RAM, while dev only has 16 GB, prod has 16 cores, while dev only has 4 cores. Unintuitively, this disparity can result in queries running faster in development than in production.

SQL Server has a little-known (and undocumented and unsupported) troubleshooting-related DBCC command that can be used to mimic production resource levels in your development environment. As with all undocumented features, do not try this in production.

Read on to learn how DBCC OPTIMIZER_WHATIF can lead the optimizer to choose different plans.  I almost never use this command, but it is helpful to have it in your back pocket.

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Package References And ssisUnit

Published 2018-07-09 by Kevin Feasel

Bartosz Ratajczyk shows us a few methods for setting package references in ssisUnit:

When you set the packages’ references in the ssisUnit tests you have four options for the source (StoragePath) of the package:

  • Filesystem – references the package in the filesystem – either within a project or standalone
  • MSDB – package stored in the msdb database
  • Package store – packages managed by Integration Services Service
  • SsisCatalog – references the package in the Integration Services Catalog

In this post, I will show you how to set the package reference (PackageRef) for each option.

Read on for an example of using each method.

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Running ssisUnit In MSTest

Published 2018-06-18 by Kevin Feasel

Bartosz Ratajczyk shows how to convert ssisUnit tests to work with the NUnit or MSTest frameworks:

MSTest v2 is the open source test framework by Microsoft. I will not write a lot about it. If you want to learn more – read the excellent blog posts by Gérald Barré.

I took the idea and parts of the code from Ravi Palihena’s blog post about ssisUnit testing and his GitHub repository. Then I read the source code of the SsisUnitTestRunner, SsisUnitTestRunnerUI and posts by Gérald and changed the tests a bit.

I will use MSTest to execute ssisUnit tests from the file 20_DataFlow.ssisUnit. For that, I created a new Visual C# > Test > Unit Test Project (.NET Framework) – ssisUnitLearning.MSTest – within the solution. I also set the reference to the SsisUnit2017.dll and SsisUnitBase.dll libraries and loaded required namespaces

Bartosz gives us the initial walkthrough, and then builds a T4 template to automate the task.  You can grab that template on his GitHub repo, and hopefully something makes its way into ssisUnit to make integration with NUnit / MSTest official.

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Cached Datasets And ssisUnit

Published 2018-06-04 by Kevin Feasel

Bartosz Ratajczyk shows how to store result sets in a test file with ssisUnit:

The ssisUnit GUI does not support creating the persisted dataset. If you switch the IsResultsStored flag to true on the dataset’s properties, it gives a warning “The expected dataset’s (<the dataset name>) stored results does not contain data. Populate the Results data table before executing.” during the test run.

To find out more about it, take a look at the source code.

This is a nice explanation of a current limitation in the tool and a workaround.

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nUnit Tests And Spatial Data Types

Published 2018-05-23 by Kevin Feasel

David Wilson shows how to build integration tests in nUnit when you’re using spatial data types:

I was recently working on a .NET 4.6 based project that was using EF 6 and nUnit for unit testing. While setting up some integration tests against a local SQL database I was receiving this error:

Spatial types and functions are not available for this provider because the assembly ‘Microsoft.SqlServer.Types’ version 10 or higher could not be found.

We had recently been using SQL Server spatial types for tracking geograpic locations and the tests which performed updates and inserts against these fields were failing.

Read on for the setup instructions.

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Unit Testing ETL Processes

Published 2018-05-02 by Kevin Feasel

Ed Elliott has a post showing how to perform unit testing on ETL processes:

In tSQLt, we can call tSQLt.FakeTable and then do an insert, if we don’t use tSQLt what do we do? Well, we need to setup the data we want, this could be by using a tool or by writing a load of insert statements. I have seen this done in various ways such as:

  1. Writing manual insert scripts
  2. Using a tool to setup the data
  3. Making use of API’s in the application to setup the data we need
  4. Some wierd and wonderful things that we shouldn’t recommend

Ultimately, for each test that you do you need to know what data you need for it. There isn’t really any way around this, and the sooner you get yourself in the position where you can setup the data you need for a test, the better.

Read the whole thing.

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Running dbachecks In Parallel

Published 2018-04-27 by Kevin Feasel

Caludio Silva shows how you can run multiple instances of dbachecks concurrently:

Imagine that I want to check for databases in Full Recovery Model on the production environment and I want to start (in parallel) a new check for the development environment where I want to check for Simple Recovery Model if this setting is not changed in the correct time frame, we can end checking for Full Recovery Model on the development environment where we want the Simple Recovery Model.

The first time I tried to run tests for some environments in parallel, that had the need to change some configs, I didn’t realise about this detail so I ended up with much more failed tests than the expected! The bell rang when the majority of the failed tests were from a specific test…the one I had changed the value.

Read the whole thing before you start running Task.Parallel or even running multiple copies of dbachecks in separate Powershell windows.

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Verifying SSIS Database Connections With ssisUnit

Published 2018-04-16 by Kevin Feasel

Bartosz Ratajczyk shows how to test project-level connections in SQL Server Integration Services with ssisUnit:

Previously we successfully prepared tests for variables and parameters using VariableCommandand and ParameterCommand. Now it’s time to communicate with the database, and for that, I will use connection manager defined on the project level. I know from the ssisUnit tutorials it works perfect with package connection managers, so it’s time to verify it against the projects. I will test the package 10_ProjectCM.dtsx – it is just getting a single value from the table in a database and storing it in a variable. All the packages and unit tests are on my GitHub.

The package contains three SQL Tasks: the first just checks if we can communicate with the database using SELECT 1 statement, the second gets the information from the table, and the third repeats the second on the container level.

Click through for the tests.

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Getting Started With ssisUnit

Published 2018-03-29 by Kevin Feasel

Bartosz Ratajczyk builds a few SQL Server Integration Services unit tests with ssisUnit:

The result shows 1 test run, 1 test passed, 2 asserts run, 2 asserts passed.

Wait, what? We have prepared only one assert, why does it show two?

The second assert is: “Task Completed: Actual result (Success) was equal to the expected result (Success).“. Great. Where does it come from? Let’s find out.

This is a nice introduction to the topic; if you fuss about with SSIS packages, you should check this out.

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