Sql-Server

AzureCon is this month–register now!

AzureCon is the main #Azure related conference each year, and of course, it’s an online conference.

It’s coming up at the end of this month (September).

It’s time to register to see what ScottGu and the people from the Azure team have to tell us.

NOTE: This event is now closed

2015-09-10

FIX: Internal service error when refreshing Personal Gateway for Power BI

We recently started working with the new Personal Data Management Gateway for Power BI. Overall, we really like it but the error messages in most of Power BI have left much to be desired.

One error that we were encountering made us feel like the service was flaky as it seemed to happen randomly. When we tried to refresh a dataset, we got this error:

RefreshError

The Power BI team came to the rescue and worked out what was happening. Turns out that you cannot currently refresh more than once every 5 minutes. That also includes within 5 minutes of your initial upload. Unfortunately, this is the error returned when you attempt it.

2015-07-14

Cannot determine next value for a sequence

One of the most anticipated new features in SQL Server 2012 was the introduction of sequences. Prior to SQL Server 2012, developers had a choice of IDENTITY columns or a roll-your-own table mechanism.

Sequences allow us to create a schema-bound object that is not associated with any particular table. For example, if I have a Sales.HotelBookings table, a Sales.FlightBookings table, and a Sales.VehicleBookings table, I might want to have a common BookingID used as the key for each table. If more than the BookingID was involved, you could argue that there is a normalization problem with the tables but we’ll leave that discussion for another day.

2015-06-23

Plan Cache Pollution: Avoiding it and Fixing it

While SQL Server’s plan cache generally is self-maintaining, poor application coding practices can cause the plan cache to become full of query plans that have only ever been used a single time and that are unlikely to ever be reused. We call this “plan cache pollution”.

Causes

The most common cause of these issues are programming libraries that send multiple variations of a single query. For example, imagine I have a query like:

2015-06-03

Mixing UNION and UNION ALL and other oddities seen in consulting

I always say that one of the things that I love about consulting or mentoring work is that I see things (mostly code) that I would have never have thought of, both good and bad. You could spend all day dreaming up bizarre ideas and never come close to the ones that I just happen to come across.

A good example of this was a site I was at a while back where every table had a GUID name. Yes, I’m talking about tables named dbo.[3B38AB7E-FB80-4E56-9E5A-6ECED7A8FA17] and so on. They had tens of thousands of tables named this way. Query plans were close to unreadable.

2015-05-28

Data Camp Sydney (Free)

Hi Folks, on the 5th June (yes that’s Friday next week), I’m running a Data Camp day for the local Microsoft team. It’s being held at Cliftons in the city.

We’ve got four topics for  the day:

  • Azure SQL DB
  • Azure DocumentDB
  • Azure Machine Learning
  • Azure Stream Analytics

If you want to get your head around any/all of these, we’d love to see you there. Places are limited but you must register and can do so here: https://msevents.microsoft.com/CUI/EventDetail.aspx?EventID=1032627085&Culture=en-AU&community=0

2015-05-25