So . . . here I am playing around with PowerPivot to get ready for a demo. As this is a group from the SharePoint dev team (actually SharePoint Online), I wanted to include some cool SharePoint functionality [...]]]> Updated 28-Oct-2010: Some folks are reporting that an iisreset is needed to make the updates visible to SharePoint.

So . . . here I am playing around with PowerPivot to get ready for a demo. As this is a group from the SharePoint dev team (actually SharePoint Online), I wanted to include some cool SharePoint functionality into the demo. Trying to be cool and ‘wow’ them, I decide to use a SharePoint list as a data source. I want to show the data mashup capabilities of PowerPivot so I have the bulk of my demo come from the Contoso sample database (the three product catalog tables) and the 4 million row Sales Fact table.

I create my SP list by extracting the 11 distinct manufacturers – and I assign them to a ‘shipper’ that I made up.

When I go to SharePoint an click on:

PowerPivot comes up but it returns an error:

"For security reasons DTD is prohibited in this XML document. To enable DTD processing set the ProhibitDtd property on XmlReaderSettings to false and pass the settings into XmlReader.Create method."

So it turns out that I forgot (it happens to the best of us) to install the ADO.NET Data Services 3.5 SP1, located here: http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=3e102d74-37bf-4c1e-9da6-5175644fe22d

Which I would have known if I had taken my own advice and read BOL beforehand. Read the “New server” installation notes here: http://msdn.microsoft.com/en-us/library/ee210708.aspx#nextsteps

So the moral of the story is: RTFM

After installing ADO.NET Data Services on my SharePoint site, I was able to bring up the data feed in PowerPivot – setup the relationship between the Manufacturer field in the SharePoint list and the Manufacturer field in the Contoso database and I was off and running . . . I also setup daily data refresh job . . . and I could see the Gallery snapshot changing as I entered new data into the SharePoint list . . WOW!

Enjoy!

So I am very sensitive and want to ensure that users become knowledgeable of its ‘quirks’ as well. Here is a good one. [...]]]> I always am on the look out for cool applications that use data feeds. Personally I think that it is by far the most interesting new concept in data interchangeability in many years.

So I am very sensitive and want to ensure that users become knowledgeable of its ‘quirks’ as well. Here is a good one. Recently I had an email sent to me from a user who was reporting that Reporting Services as returning a very difficult error to understand when he used a data feed. The error is:

Unable to obtain schema for data feed ‘<name>’. Please make sure this feed exists.

Here is a screen shot:

To understand the source of the problem, you have to understand how Reporting Services works. In particular, you have to understand how parameters are handled in Reporting Services. Parameters to a report allow you to change how the report is generated. For example, you could have a field called “Department” and then have a list of departments for that field. The end-user can select which departments he or she wants to report on. The problem is that these are passed on the URL to the report. The URL for a Reporting Services report looks something like:

http://<server>/Reporting/_vti_bin/ReportServer?http%3a%2f%2f<name>%2fReporting%2fHiddenReports%2f<name>.rdl&amp;param<name>=<value>;param<name>=<value> . . .

All of the parameters are included in the URL and you will find that they are urlencoded (so they are even longer). Reporting Services (and IE) has a limit of 2048 characters. We’ve seen this problem several times and it is real easy to get into when you have long folder names, are passing many, many parameters, or if the parameters themselves have long values. Interesting, while the PowerPivot import wizard is reporting issues around obtaining the schema, if you dug deeper (with something like a http tracer) you would have seen a WebException “The remote server returned an error: (414) Request-URI Too Long.”

The Url length limit in IE is documented here: http://support.microsoft.com/kb/208427

The only workaround is to modify the report so it takes less parameters or values that shorten the resulting URL, such as using integers instead of long strings, or GUIDs that identify combinations of parameters.

Enjoy!

_-_-_ Dave

Abstract: PowerPivot, a new add-in for Excel, can absorb and analyze vast quantities of data. And it can ingest that data from sources that support that Atom-based OData protocol. John Hancock, who led the charge to add support for data feeds to PowerPivot, tells host [...]]]> Very cool podcast with John Hancock concerning data feeds – http://itc.conversationsnetwork.org/shows/detail4453.html

Abstract: PowerPivot, a new add-in for Excel, can absorb and analyze vast quantities of data. And it can ingest that data from sources that support that Atom-based OData protocol. John Hancock, who led the charge to add support for data feeds to PowerPivot, tells host Jon Udell how it works, why it supports OData, and what this will mean not only for corporate business intelligence but also for the analysis of open public data.