SharePoint Workspace and the Office Document Cache

There are three storage mechanisms SharePoint Workspace uses to store data on your local computer. Lists, InfoPath forms, schema, and views are stored in SharePoint Workspace itself, BCS data has its own storage mechanism, and your SharePoint documents are stored in a common Office file store called the Office Document Cache (ODC). The diagram below shows the relationships between the three data stores and the content sources for each.

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The Office Document Cache

SharePoint Workspace, along with other Office 2010 products, uses the Office Document Cache (ODC) for file storage. Files are downloaded and synchronized using a protocol called File Sync via SOAP over HTTP (FSSHTTP). SharePoint Workspace’s use of the ODC and FSSHTTP has many advantages for XML-based Office documents, including:

· Reduced network load

· Faster saves

· Conflict resolution

· Coauthoring

Differential Sync

After initial sync, only document changes are sent between SharePoint and SPW. This reduces bandwidth consumption and server load, while giving the user a more responsive save experience, even when working with very large files.

Collaborating Online and Offline with Coauthoring and Merging

When you’re offline and working with SharePoint documents, other users may be editing the same document, putting it in conflict when you try to sync your changes. SharePoint Workspace and the ODC handle many of these changes automatically for you, by seamlessly integrating your changes with the updated document on the server. When you get back online, your changes will be merged with the new server copy and any changes on the server will appear highlighted green.

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Coauthoring allows multiple users to edit the same document at the same time collaboratively. You will be notified when you open a document someone else is editing, along with easy access to their contact information.

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When the other user makes changes to a section of a document, that section will become locked, shown below. Once the user has completed making changes you will be notified and the new changes can be merged into your work.

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High Volume Synchronization

We’re actively working on increasing capacity limits to optimize throughput, but for now synching a large number of documents can degrade performance.  SharePoint Workspace will first warn you when the number that you’re scheduled to synchronize gets high, and then it will actually change its behavior when the number gets higher still.

If you are syncing 500 or more documents, SPW will give you a warning, which also serves as a heads-up to suggest that you should expect gradually slower performance as the number of documents gets larger.

When you’re about to synch 1800 documents or more, SharePoint Workspace will change its behavior to make sure that you get your documents in a timely fashion.  It will synchronize only headers (metadata about the document) at this point, and will synchronize actual documents only on demand.  When you actually need one or more documents, you can click on them, and SPW will sync them for you on the spot.

There are several ways to reduce the number of documents you have offline, such as deleting unused SharePoint workspaces, disconnecting from unused document libraries, or discarding local copies of documents.

Note that these limitations apply to the ODC only and do not apply to Groove workspaces.

 

Andrew Harris and Jim McCoy