Articles

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.

2017-10-19

3,623 reads

SQL Server AlwaysOn Availability Groups Using an Azure Template

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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.

2017-10-18

3,292 reads

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.

2017-10-17

3,790 reads

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.

2017-10-16

5,024 reads

A Lightweight, Self-adjusting, Baseline-less Data Monitor

by Alex Chamchourine

SQLServerCentral.com

data monitoring

Can data alert us that something is going on, without baselines and thresholds?

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2017-10-13 (first published: 2016-02-23)

4,143 reads

Discuss

Statistics in SQL: Student’s t-test

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SimpleTalk

statistics

Many undergraduates have misunderstood the name 'Students' in the t-test to imply that it was designed as a simple test suitable for students. In fact it was William Sealy Gosset, an Englishman publishing under the pseudonym Student, who developed the t-test and t distribution in 1908, as a way of making confident predictions from small sample sizes of normally-distributed variables. As Gosset's employer was Guinness, the brewer, Phil Factor takes a sober view of calculating it in SQL.

2017-10-12

3,767 reads

Network Configuration of SQL Server Always On Availability Groups in Azure

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Database Journal

always on

Implementing SQL Server Failover Clustering in Azure virtual machines differs in several aspects from its on-premises implementations. These differences reflect some of the unique characteristics of the storage and network infrastructure services in the Microsoft cloud environment. In this article, Marcin Policht looks at the networking aspects of clustered deployments of SQL Server 2016 in Azure.

2017-10-11

2,735 reads

Automated Database Provisioning for Development and Testing

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SimpleTalk

provisioning

If your development team needs to work on anonymised copies of the current production database, and if changes are being delivered rapidly as well, that could mean a lot of time and routine DevOps work copying databases. SQL Clone was designed for tasks like this. Grant Fritchey investigates whether you save time, effort and scripting over the more traditional approach, and at what point it makes sense to use it.

2017-10-10

4,465 reads