Crawled properties are metadata—for example, Author or Title—extracted from documents when the document is crawled. A crawled property, such as Author, may be held in different content sources but use a different term to describe the same thing. For example, one source may use Writer whereas another user may use Contributor. Author, Writer, and Contributor all mean the same thing, You can create a single managed property to which all the other crawled properties are mapped. That means that you have a managed property—Author—and you map other crawled properties—Author, Writer, and Contributor—to that one managed property. Your managed properties can appear in refined searches and help users perform more successful queries. Refined searches can be performed only on managed properties, not crawled properties. In SharePoint 2013, an administrator can create managed properties down to the site collection level. This enables the designer to define custom attributes associated with business data for purposes of filtering, reporting, and refining. Managed properties can still be created at the Search service application level. In SharePoint 2010, it was necessary to run a full crawl of all content to create a crawled property, and an additional crawl to create a managed property. This has been changed in SharePoint 2013. Now, when an administrator creates a site column, it is automatically configured to be a managed property before the crawl.
To create a new managed property, you can go into the Site Settings and then Search Schema in the Site Collection Administration section. From this page, you can create a new managed property and map it back to the crawled property.
There are three limitations on managed properties at the site collection level:
- They can only be text.
- They cannot be sortable.
- They cannot be refinable.