Subscriptions Overview
Microsoft® SharePoint™ Portal Server Subscriptions allow a user to create subscriptions to content on the dashboard site, and be notified when changes to the content occur. Users are notified of changes to individual documents, folders, categories, or search results. Users can view notifications on the Subscriptions Summary Web Part or on the Subscriptions page of the dashboard site. Subscriptions update notifications can also be sent to users by e-mail. To view the Subscriptions dashboard, users must have reader permissions for the dashboard site and subscriptions dashboard folder. Users can create or delete subscriptions at any time. Workspacecoordinators can only delete a user's subscriptions.
Subscriptions are implemented by using Persistent Query Service (PQS) rules. PQS is a reverse query processor. It evaluates a large set of queries against a single item to determine which queries match the item. This allows matching subscriptions to be identified as each new document arrives in the SharePoint Portal Server store.
This matching process takes place when new content is crawled by the Search service. The Gatherer component of the Search service processes document information. One of the Gatherer's components, the Subscriptions plug-in, provides the PQS plug-in content, content properties, and other information about the document being crawled. The PQS plug-in checks the data in the stream against the workspace subscriptions rules.
Note
There are differences between the SharePoint Portal Server SQL query syntax and the PQS query language. To see a list of these differences, see Subscription Query Language.
If any matches were found between the filtered content and a subscription query, PQS provides a list of the matches to the Subscriptions plug-in. Further security checks are performed on the data and the matching results are stored in XML format in the property store used by Search. The Subscriptions Summary Web Part on the dashboard site and the subscription notification process look for results at this location. Notifications on the dashboard site are always available immediately. Notification tasks can be scheduled to send e-mail notifications immediately, daily, weekly. All notification tasks are Microsoft Windows® 2000 Scheduled Tasks and can be configured through the Windows Control Panel.
Related Topics
SharePoint Portal Server Dashboard Web Parts