Professional SharePoint® 2007 Web Content Management Development: Building Publishing Sites with Office SharePoint Server 2007

8.3. Performance and Usability Considerations

Because navigation controls appear on nearly every single page in a content-centric site, anyone implementing Publishing sites should exercise caution when creating such sites. A poorly performing navigation control can cripple a page and even an entire site. Attention should also be paid to the usability of the navigation controls. If the site's users cannot make sense of or easily use the site navigation, it is not serving its purpose and should be addressed.

8.3.1. PortalSiteMapProvider

The navigation controls provided in MOSS — specifically, the navigation providers — utilize a very powerful and performant object called Microsoft.SharePoint.Publishing.Navigation.PortalSiteMapProvider. The job of the PortalSiteMapProvider is to expose the SharePoint site hierarchy to site map data sources that can then massage the hierarchy before passing it along to the rendering controls. One of the unique characteristics of the PortalSiteMapProvider is the component's performance. It boasts a sophisticated, built-in caching mechanism to ensure that navigation controls are never the cause for a poorly performing site, and it has been optimized for cross-list and cross-site queries. However, like many other things in SharePoint, it cannot cross the boundaries of site collections.

When the PortalSiteMapProvider receives a request for data using one of the retrieval methods, it queries the data in SharePoint to obtain a set of results. It inserts ...