Databases used by SharePoint 2010
In this article I am describing the changes in the Microsoft SharePoint Server 2010 database. What databases are used by SharePoint 2010 for various services.
If you think about SharePoint 2007, it stores all content in large tables and there can be performance problems caused by SQL Server locks. When a large number of people use the same content and SQL Server has locked the table, then no one can work untill the user that generated the lock releases the content. So we are limited to 2000 items in List and should use several Site Collections when the Application is large. Now just think about how SharePoint 2010 solved this issue? Simple, by moving content from single tables into multiple tables. Such changes allow us to store millions of items in SharePoint. Now we can check each database in detail.
The Administration Database is same the as the Shared Services Provider database in MOSS 2007 and is instantiated once per Search application aligning with the Administration Component.
The Property Database stores crawled properties associated with the crawled data to include properties, history data, etc.
Crawl Database is the Search database in MOSS 2007.
The configuration database handles all administration of the deployment as well as re-direction of requests to the appropriate database. It also manages the load-balancing for the back-end databases. When a WFE server receives a request for a page in a particular site, it checks the configuration database and identifies which content database grips the site's data. The configuration database concepts are the same as we have seen in MOSS 2007. In Microsoft SharePoint Server 2010 the Sitemap is serialized to disk to improve performance and reduce database callback operations.
The back-end content database stores all site content, including site documents or files in document libraries, list data, and Web Part properties, as well as user names and rights. All the data for a specific site resides in one content database on only one computer. We can configure RBS as an alternative to this. I already have an article about configuring RBS in SharePoint 2010. Please refer to that for more details about it.
User Profile Service
The user profile database is a flexible database that stores and manages user and associated information. The database allows for a flexible schema that supports multiple data types. It can be queried and it can be updated.
The synchronization database is used to store configuration and staging data for synchronization of profile data from external sources such as Active Directory.
Social Tagging Database
The social tagging database stores social tagging records and their respective URL which are coupled with information from the profile and taxonomy databases at the front-end layer at execution/request. This database is used to store social tags and notes created by users.
For more details you can refer the TechNet article at: