Posts Tagged ‘OLAP’

Data-related tips & tricks from around the web

August 21, 2008

You’ve probably noticed that you shouldn’t trust this blog for real-time news tracking. The following are essentially timeless, however, so here we go…

Rob van Gelder (of DailyDoseOfExcel fame) shared a tip back in May on how to build a simple Gantt chart in Excel. I’m posting a link here because it’s the easiest I’ve seen so far.

Jeff Smith exposes his Golden Rule of data Manipulation over at sqlteam.com. While he elaborates on his statement from a programmer’s standpoint, it’s all applicable to knowledge workers and spreadsheets:

“It is always easier and more flexible to combine data elements rather than to break them apart”

From a data analysis standpoint, Jeff’s examples are essentially related to what I would call attributes (such as phone numbers). His rule still holds true with values, though. As you work towards summarizing a data set (say, daily financial transactions that you want to analyze by month), you’ll want to aggregate values as late as possible instead of running the risk of losing valuable information by aggregating too early. Spreadsheet programs hit a limit between 65k and 1M records, but there are tools to take it from there – which brings us to Paul Steynberg’s advice for considering OLAP tools as part of a financial system manager’s toolbox.

OLAP technologies are particularly well suited to handling large amounts of data. I personally share Paul’s opinion of Microsoft’s SQL Server Analysis Services, which I would describe to the non-initiated as Excel on steroids. On lots of steroids, that is. SSAS gives you access to summaries and advanced computations based on millions of underlying records, usually responding in just a few seconds.

EDIT (Sep. 10, 2008): Using a definition as crude as “Excel on steroids” for SSAS left me feeling a little guilty. I’m over it now, having just read Andrew Fryer’s post on business intelligence for small business;-)

OLAP Quickies

August 29, 2007

I can’t seem to find the original Hugh McLeod quote Andrew Fryer is referring to, but here is how it goes anyway:

On-Line Analytical Processing (OLAP) is actually about business, it just sounds like a science project.

This potential confusion is one more hint that this field (multidimensional modeling and analysis but really Business Intelligence in general) requires both technical skills and business acumen. Probably just another argument in favor of Business Intelligence Competency Centers

Still on the OLAP front, a new (beta) version of Palo is available. Wikipedia has a short summary:

Palo is a memory resident multidimensional (OLAP or MOLAP) database server [...] typically used as a Business Intelligence tool for Controlling and Budgeting purposes with Microsoft Excel as a user interface. Beyond the multidimensional data concept, Palo enables multiple users to share one centralised data storage (“Single version of the truth“).

There’s a (somewhat old) discussion thread here. I only played 10 minutes with it – it seems to offer many interesting features. You can also apparently connect Palo and Microsoft Analysis Services using software from Cubeware.

XLCubed acquires BonaVista Systems, publisher of MicroCharts

August 14, 2007

Now this is interesting. Not only do the XLCubed and MicroCharts Excel add-ins work much better together today than when I originally wrote about combining them, but the publisher of the former has actually acquired the publisher of the latter. This is extracted from the message that went out to MicroCharts users:

Linking XLCubed with MicroCharts connects Dashboards direct to the data and makes them dynamic. It also makes them easier to build as the OLAP Cube can also store the control information for the dashboard as well as the data.

This sounds promising, particularly if microcharts are made available within XLCbubed grids. Formula-mode integration is perfect for dashboard-style reporting but remains limited for dynamically exploring data. More on all this when I’ve had a chance to actually try the “integrated” version.

MDX tips from one of the masters

June 22, 2007

Chris Webb shared several valuable tips recently that I want to post here for future reference:

Once more, I’m unfortunately only referencing someone else’s content but this is too good to pass up.

The power of Excel-friendly OLAP

February 12, 2007

Dick Kusleika pointed a few days ago to a paper by Charley Kyd. In it, Charley gives a convincing overview of the possibilities revealed by OLAP-powered Excel solutions. Speaking from experience, I can only attest to the amazing things this combination allows you to achieve.

I’m surprised by Charley’s statement that TM1 and PowerOLAP “return data to Excel about 100 times faster than Analysis Services does”, but then I haven’t tested either to compare it to SSAS coupled with XLCubed. This combination is so fast already that I’m not sure how a user would pick up a 100-times increase in query speed. The article is nonetheless very much worth reading, particularly if the combination of OLAP and Excel sounds new to you.

If you think you’re familiar with cubes because you’ve used Business Objects before, you may want to check out my post comparing Business Objects Universes (and cubes) to the cubes provided by Microsoft Analysis Services.

MDX Trick: Top 10 Plus Other Query

January 5, 2007

Here is – essentially for my own future reference – a trick that Reed Jacobson posted a while ago. I didn’t use it yet but this will come in handy at some point.

WITH
SET [TCat] AS TopCount(
[Product].[Subcategory].[Subcategory],10,[Measures].[Sales Amount]
)
MEMBER [Product].[Subcategory].[Other] AS
Aggregate([Product].[Subcategory].[Subcategory] – TCat)
SELECT { [Measures].[Sales Amount] } ON COLUMNS,
TCat + [Other] ON ROWS
FROM [Adventure Works]
;

The (Steep) SQL Server 2005 Learning Curve

November 1, 2006

Stephen Swoyer has published a brief analysis at TDWI on why the SQL Server installed base seems to be growing relatively slowly. Bottom line: the learning curve is steep and corporations cannot easily replace prior SQL Server versions running mission-critical applications.
You’ve got to love his quote of Adam Machanic (SQL Server MVP) saying that “comparing DTS to SSIS… would be like comparing a pea shooter to a neutron bomb[…]”. I’ve been rather more involved with Analysis Services than Integration Services, but this is exactly the way I’ve felt about the OLAP side of things…
As far as desktop data management goes, the big news with Microsoft’s latest release has got to be the free SQL Server Express Edition. From a data storage & processing standpoint, this is a interesting alternative to Microsoft Access. You may still need the latter (or another Office component such as Excel) as a graphical interface into your data, but if you’re expecting your requirements to grow, this will be much easier to scale to an enterprise version when required.

Updated: Learning curve or not, this version of Microsoft’s database offering is worth the effort, according to some.

Cubes and Universes

May 24, 2006

Mark Miller recently posted a link to a whitepaper comparing the BI offerings from Business Objects and Microsoft. This is something I had been looking for for quite a while and I think it does a good job of presenting a comparative history of both platforms. The content remain fairly high level, though. What I’d like to do here is to discuss some of the conceptual differences between a Business Objects (BO) universe and a Microsoft SQL Server Analysis Services (SSAS) cube.

As you read through this brief comparison, please keep in mind the following:

(more…)


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