Microsoft Sharepoint Products and Technologies Resource Kit eBook

98 Part II: SharePoint Products and Technologies Architecture
Back-End Databases
Whether a separate SQL Server or WMSDE is used, the back-end server in Windows
SharePoint Services creates and uses back-end databases. The purpose of having
two database types is to separate the site data from the configuration information. A
database that contains site data is called a content database, while product information
and settings are contained in what is called a configuration database. There can
be a single content database in a small environment, but in a large environment
there can be hundreds or even thousands of content databases. No matter how
many content databases exist in a Windows SharePoint Services farm, there is only
one configuration database.
Configuration Database
In a Windows SharePoint Services environment, there can be multiple front-end
Web servers that contain several websites whose content is stored in one of a number
of back-end content databases. To keep the front-end Web servers stateless, a
centralized database is needed to keep track of which content database holds the
data for a specific site. When a front-end Web server receives a request for a page
from a site, the first connection it must make is to this configuration database. For
performance reasons, this information is cached on the front-end Web server for
subsequent requests and the cached information is used by the front-end Web server
thereafter.
Content Database
Content databases provide content to the front-end Web servers when it is
requested. All site content—including site documents, list data, Web Part properties,
as well as user names and rights—are stored in content databases. You can create as
many content databases as needed to support the websites on your servers. This can
range from just one to thousands, depending on the number of users.
Physical Configurations
With the split of front-end and back-end services, administrators now have the flexibility
to configure Windows SharePoint Services in several ways. By providing any
configuration from a single server to a server farm, Windows SharePoint Services
can scale to suit small to large organizations.
An organization with fewer users can start with a single-server installation of
Windows SharePoint Services. This means that both the front-end and back-end
components are installed on the same physical server. In this configuration, WMSDE
can be used for the back-end databases instead of SQL Server. If the number of users
in an organization grows enough to require a physical separation of front-end and
back-end components, the WMSDE databases can be migrated to SQL Server. To do