Microsoft SQL Server 2008 R2 810-08234 Benutzerhandbuch

Produktcode
810-08234
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PowerPivot for SharePoint 
CHAPTER 10
 
203
balancing across servers for query processing if multiple servers are available . Furthermore, 
the PowerPivot System Service manages the connections for active, reusable, and cached 
connections to PowerPivot workbooks, as well as administrative connections to other Power-
Pivot System Services on the SharePoint farm .
To speed up access to data, the PowerPivot System Service caches a local copy of a work-
book and stores it in Program Files\Microsoft SQL Server\MSAS10_50 .POWERPIVOT\OLAP\
Backup . The service unloads this copy of the workbook from memory if no one has accessed 
the workbook after 48 hours and deletes it from the folder after an additional 72 hours of 
inactivity . If a user updates the workbook in SharePoint and a copy of the workbook already 
exists in the cache, the PowerPivot System Service also removes the older cache copy .
The PowerPivot Database
Each service application has its own relational database, called the PowerPivot database . In 
particular, this PowerPivot database stores the load or cache status of workbooks, server usage 
information, and schedule information for data refresh operations. More specifically, the 
application database stores an instance map that identifies whether a workbook is currently 
loaded on the server or in the cache . Usage information in the application database applies to 
connections, query response times, load and unload events, and other information pertinent to 
server health statistics . The data refresh schedule information includes details about data sources, 
users, and the workbooks associated with a schedule . None of the workbook content is in the 
PowerPivot database . Instead, workbooks are stored in the SharePoint content database . 
The PowerPivot Web Service
The PowerPivot Web Service is a thin middle-tier connection manager implemented as a Win-
dows Communication Foundation (WCF) Web service that runs on a SharePoint Web front end . 
The Web service listens on the port assigned to a Web application enabled for PowerPivot, and 
responds to requests by coordinating the request-response exchange between client ap-
plications and PowerPivot for SharePoint instances in the farm . This Web service requires no 
separate configuration or management.
The PowerPivot Managed Extension
The PowerPivot Managed Extension is an assembly in the Analysis Services OLE DB provider 
client . This provider client is installed on a client computer when you install the PowerPivot 
for Excel add-in, and on the SharePoint server when you install PowerPivot for SharePoint . For 
managed connections, the Web service and the managed extension operate the same way . 
The query processing request determines which one is used .