Upcoming Conferences – Fall and Winter 2016

The next months are going to be quite busy for me. There will be a lot conferences and events which I will attend and where I am also speaking. I am always happy to attend those events as it is a great place to interact with other community members and learn new stuff about the latest and coolest new tools. So lets get started:

The first conference is the SQL Saturday #546 in Oporto (Portugal) on the 1st of October where I will be speaking about “What’s new in Analysis Services 2016”.
PASS_SQL_Saturday_546_Oporto
It is the first time for me to speak in Porto but from what I heard from other people it is said to be a really great event so I am really looking forward to it!

The week after – on the 6th of October – I will be speaking at the “Virtuelle SQL Server 2016 Konferenz” (German only) where I will be doing a session on SQL Server Polybase. As the name implies, it is virtual and you can attend from wherever you are at the time. Another important thing is that it is for free! You just need to register and you’ll get two full days of sessions around SQL Server and the Microsoft Data Platform.

In the same week, the SQL Saturday #555 in Munich (Germany) is taking place.
PASS_SQL_Saturday_555_Munich
Another free event for all community members. Again, just make sure you register in time to get a ticket! I will do a more advanced session on Polybase there with a more technical focus. So even if you attended the virtual event before, this might still be of great value for you!

Later in October, the world’s biggest conference about the Microsoft Data Platform and all other related technologies – the PASS Summit – will be in Seattle again, attracting 4,000+ attendees every year.
PASS_Summit_2016
It’s probably a bit late but you can still register for this great event. Unfortunately, I forgot to submit some sessions for this conference so I won’t be there this year. (Note to myself: submit sessions for 2017!) Having been there already several times, I can only recommend this conference to anyone who is into Microsoft, it’s Data Platform and everything around it.

For January 2017, I am very happy to announce that our SQL Saturday #579 in Vienna (Austria) is taking place the 4th year in a row now.
PASS_SQL_Saturday_579_Vienna
We had 250+ attendees last year and we are definitely aiming to hit the 300 mark this year! Again, it is free and you just need to register as soon as possible. (In case you cannot make it later on, please unregister as early as possible as otherwise you take away the slot of someone else). The Call for Papers is still open so if you want to speak at the event, simply submit your session details there.

Last but not least, the SQL Server Konferenz 2017 will be back in Darmstadt as in the previous years.
PASS_SQL_Konferenz_2017
This means 3-4 full days of sessions and trainings around the Microsoft Data Platform. Overall an awesome event organized by PASS Germany. It is also the 5th time in a row this year and believe me, they have organized and optimized everything down to the tiniest detail making it one of the best and biggest conferences in whole Europe!
I already submitted some sessions and I am hoping to be selected to speak there.

As you can see, a lot of things are ahead but I am really looking forward to all of them!

Upcoming Events I am speaking at in June 2015

I am very glad that I got selected as a speaker for two upcoming SQL Saturdays in June. First there is the SQL Saturday #409 in Rheinland, Germany  on June 13 and the week after the SQL Saturday #419 in Bratislava, Slovakia on June 20.

For those of you who are new to the concept of PASS SQL Saturdays, this is a series of free-of-charge events all around the globe where experienced speakers talk about all topics around the Microsoft SQL Server platform and beyond. As I said, its free, you just need to register in time in order to get a ticked so better be fast before all slots are taken!

SQLSaturday_409_Rheinland_Germany

I will do a session together with my colleague Markus Begerow (b, t) on “Power BI on SAP HANA” – two technologies I got to work a lot with recently. We are going to share our experience on how to use Power BI to extract data from SAP HANA, the different interfaces you can use and the advantages and drawbacks of each. Even tough it is considered a general sessions, we will also do a lot of hands on and elaborate on some of the technical details you need to be aware of, for both, the Power BI side and also for SAP HANA.

 

SQLSaturday_419_Bratislava_Slovakia

In Bratislava I will speak about Lessons Learned: SSAS Tabular in the real world where I will present the technical and non-technical findings I made in the past when implementing SSAS Tabular models at larger scales for various customers. I will cover the whole process from choosing SSAS Tabular as your engine (or not choosing it), things to consider during implementation and also shed some light on the administrative challenges once the solution is in production.

I think both are really interesting sessions and I would be happy to see a lot of you there and have some interesting discussions!

Happy New Year! – How about some Conferences?

2015 just started – and it is a quickstart in terms of SQL Server conferences! There is quite a lot of upcoming conferences and I am happy that most of them are in Europe.

Below you can find a short overview followed by some more details:

What? When? Where? Am I there?
German SQL Server Conference February 3-5th Darmstadt, Germany Yes, I am speaking!
SQL Saturday Vienna February 27-28th Vienna, Austria Maybe, but not speaking
SQLRally Nordic Copenhagen March 2-4th Copenhagen, Denmark Yes, I am speaking!
SQLBits XIV Superheroes March 4-7th London, UK Yes, I am speaking!

UPDATE 2014-01-13:
I just received a confirmation that my session “Power BI on SAP HANA” was accepted for SQL Bits XIV!
It’s also the first time that I will do a session together with a Co-Speaker, my colleague Markus Begerow (b)

 

It starts with the German SQL Server Conference 2015 on February 3-5th
728x90_SQL_Server_Konferenz_EN
I am also very happy that my session “Load testing Analysis Services” was selected and I will be speaking the second time in a row at this awesome conference which is also the biggest German SQL Server Conference out there. And now worries, there are also a lot of English session in case you do not speak German Winking smile

Up next is a true marathon of conferences starting with the SQL Saturday #374 in Vienna on 28th of February.
SQLSaturday_374_Vienna
This year also featuring Pre-Cons on 27th of February!
Reza Rad (t, b) and Leila Etaati (t, b) will be speaking on “Power BI from Rookie to Rockstar” and Dejan Sarka (t, b) on “Advanced Data Modeling
Last year it was fully booked pretty soon and we had a long waiting list so better do your reservation now!
The schedule can be found here and features 20 sessions of well-know SQL Server professionals.

Directly after the SQL Saturday in Vienna the PASS SQLRally Nordic opens its doors in Copenhagen again on March 2-4.
SQLRally_2015_Copenhagen_Banner
The official schedule was just released today and can be found here (full PDF)!
I will deliver my session “Deep-Dive to Analysis Services Security” on Wednesday 4th.

Last but definitely not least is SQLBits Conferences, Europe’s biggest SQL Server conference, which is taking place the 13st time now on March 4-7 in London. (don’t get confused just because its SQL Bits XIV, Microsoft also skipped Windows 9 Open-mouthed smile). This year its all about Superheroes and a lot of SQL Server Superheroes will be there!
SQLBits_Superheroes
A schedule is not available yet but will be made public within the next days I guess so stay tuned!

UPDATE 2014-01-13:
The official schedule will soon be available here. Our Session is very likely to be on Friday.

Hope to see you there!

Another Post about Calculating New and Returning Customers

I know, this topic has already been addressed by quite a lot of people. Chris Webb blogged about it here(PowerPivot/DAX) and here(SSAS/MDX), Javier Guillén here, Alberto Ferrari mentions it in his video here and also PowerPivotPro blogged about it here. Still I think that there are some more things to say about it. In this post I will review the whole problem and come up with a new approach on how to solve this issue for both, tabular and multidimensional models with the best possible performance I could think of (hope I am not exaggerating here  🙂 )

OK, lets face the problem of calculating new customers first and define what a new customer for a given period actually is:

A new customer in Period X is a customer that has sales in Period X but did not have any other sales ever before. If Period X spans several smaller time periods
(e.g. Period X=January contains 31 days) then there must not be any sales before the earliest smaller time period (before 1st of January) for this customer to be counted as a new customer.

According to this definition the common approach can be divided into 2 steps:
1) find all customers that have sales till the last day in the selected period
2) subtract the number of customers that have sales till the day before the first day in the
selected period

 

First of all we need to create a measure that calculates our distinct customers.
For tabular it may be a simple calculated measure on your fact-table:

Total Customers:=DISTINCTCOUNT(‘Internet Sales’[CustomerKey])

For multidimensional models it should be a physical distinct count measure in your fact-table, ideally in a separate measure group.

How to solve 1) in tabular models

This is also straight forward as DAX has built-in functions that can do aggregation from the beginning of time. We use MAX(‘Date’[Date]) to get the last day in the current filter context:

Customers Till Now:=CALCULATE(
[Total Customers],
DATESBETWEEN(
‘Date’[Date],
BLANK(),
MAX(‘Date’[Date])))

 

 

How to solve 2) in tabular models

This is actually the same calculation as above, we only use MIN to get the first day in the current filter context and also subtractt “1” to get the day before the first day.

Previous Customers:=CALCULATE(
[Total Customers],
DATESBETWEEN(
‘Date’[Date],
BLANK(),
MIN(‘Date’[Date])-1))

 

To calculate our new customers we can simply subtract those two values:

New Customers OLD:=[Customers Till Now]-[Previous Customers]

 

 

How to solve 1) + 2) in multidimensional models

Please refer to Chris Webb’s blog here. The solution is pure MDX and is based on a combination of the range-operator “{null:[Date].[Calendar].currentmember}”, NONEMPTY() and COUNT().

 

 

Well, so far nothing new.

 

So lets describe the solution that I came up with. It is based on a different approach. To make the approach easily understandable, we have to rephrase the answer to our original question “What are new customers”?”:

A new customer in Period X is a customer that has his first sales in Period X.

According to this new definition we again have 2 steps:
1) Find the first date with sales for each customer
2) count the customers that had their first sales in the selected period

I will focus on tabular models. For multidimensional models most of the following steps have to be solved during ETL.

 

How to solve 1) in tabular models

This is pretty easy, we can simply create a calculated column in our Customer-table and get the first date on which the customer had sales:

=CALCULATE(MIN(‘Internet Sales’[Order Date]))

 

How to solve 2) in tabular models

The above create calculated column allows us to relate our ‘Date’-table directly to our ‘Customer’-table. As there is already an existing relationship between those tables via ‘Internet Sales’ we have to create an inactive relationship at this point:

Customer_Date_Relationship

Using this new relationship we can very easy calculate customers that had their first sales in the selected period:

New Customers:=CALCULATE(
COUNTROWS(Customer),
USERELATIONSHIP(Customer[FirstOrderDate], ‘Date’[Date]))

 

Pretty neat, isn’t it?
We can use COUNTROWS() opposed to a distinct count measure as our ‘Customer’-table only contains unique customers – so we can count each row in the current filter context.
Another nice thing is that we do not have to use any Time-Intelligence function like DATESBETWEEN which are usually resolved using FILTER that would iterate over the whole table. Further it also works with all columns of our ‘Date’-table, no matter whether it is [Calendar Year], [Fiscal Semester] or [Day Name of Week]. (Have you ever wondered how many new customers you acquired on Tuesdays? 🙂 )   And finally, using USERELATIONSHIP allows us to use the full power of xVelocity as native relationships are resolved there.

 

The results are of course the same as for [New Customers OLD]:

Result_Old_vs_New

 

Though, there are still some issues with this calculation if there are filters on other tables:

Issue_Old_vs_New

As you can see, our new [New Customers] measure does not work in this situation as it is only related to our ‘Date’-table but not to ‘Product’.

I will address this issue in a follow-up post where I will also show how the final solution can be used for multidimensional models – Stay tuned!

Download Final Model (Office 2013!)

 

UPDATE: Part2 can be found here

Back to Business – now as SSAS Maestro!

If you followed my blog in the past you have probably realized that there was no new post since mid of July. Well, there is a good reason for this – I was on vacation for the past 5 months 🙂 . At this point I want to thank my company pmOne for giving me the opportunity to do this!

I used the time to travel around in South East Asia visiting Indonesia, Singapore, Malaysia, Brunei and Vietnam and had an really awesome time and made a lot of good experiences.
During that time I also got the official confirmation that I passed the SSAS Maestro 1.2 certification that I did back in 2011 and that I am now a member of to the small circle of SSAS Maestros – what awesome news during my trip!

Now that I am back again having reloaded all my batteries, I have to catch up what I missed during that time – which is quite a lot (Office 2013, PowerView, DAX on MOLAP, …) – and pick up my old working life again.
These new technologies and tools also offer a lot of potential for future posts – so stay tuned!

 

Below are also some pictures of my travel, which are, by no means, supposed to make anyone jealous who is still sitting in the office reading this post 😉

CIMG2424 CIMG2979 CIMG4017 CIMG4094 CIMG5048 IMG_0186 IMG_0812 IMG_1274 IMG_2304