How does one get a truly random sample of data of a certain size from a SQL Server database table. Well, there are simple non-portable tricks one can use, such as the NewID() function, but then refining those can be tricky. Take the Rand() function for a start. Can it really provide you with a truly random number? Why doesn't the TABLESAMPLE clause give you a set number of rows? Joe Celko scratches his head a bit, explains some of the issues and invites some suggestions and tricks from readers.

SQL Server AlwaysOn Availability Groups Using an Azure Template

by Additional Articles

MSSQLTips.com

Availability Group (AG)

There is already a template on the Azure marketplace for setting up an AlwaysOn Availability Group. In just a few easy steps you can get a working AlwaysOn Availability Group setup, configured and running - this post describes the steps to quickly set it up.

Don’t Underestimate the Importance of Good Co-workers

by Ben Kubicek

SQLServerCentral.com

Editorial

It is important to have people that do good work and are good to work with.

Key Lookups and ColumnStore Indexes

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Brent Ozar Blog

key lookup

Erik figures out why SQL Server really doesn't like combining these two things in a query plan.

The Cloud is Better In At Least One Way

by Steve Jones

SQLServerCentral.com

Editorial

Azure SQL Database has a lot of integrity checks. Probably more than your local instance.

Timing is Everything

by Phil Factor

SQLServerCentral.com

Editorial

Phil Factor on the wise habit of timing your database routines, to avoid relying on received wisdom about performance.

The Power of Python and SQL Server 2017

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SimpleTalk

Python

Python is new to SQL Server 2017. It is intended primarily to allow the use of Python-based machine-learning within SQL Server, but it can be used for far more than this, with any Python libraries or Frameworks. To provide an example of what is possible, Hitendra shows how to use the feature securely to provide intelligent application caching, where SQL Server can automatically indicate when data changes to trigger a cache refresh.