Site Collections
What is a Site Collection?
A Site collection is a physical grouping of Sites and Subsites, which have their own set of management properties, such as owner, available features, security quotas, etc.
Why would I use multiple site collections?
Some of the benefits of using mutiple site collections in a normal SharePoint deployment include:
- Individual branding of key areas of your application
- Governance of what is available to users / moderators in different segments of your application
- Policies
- Features
- Content Types / Site Columns
- Usage reports
- Security settings
- Different Authentication models can be attributed to different site collections (Zones)
- Information that has different permission sets can be sepereated at an extra layer for increased security
- Coporate financials may be highly confidential and the extra wall a site collection can offer may be of benefit
- Seperate Content Databases for each Site Collection
- More control over backup policies for different levels of data
- Important / heavily used information can be backed up more regularly than less important information
- Smaller individual databases
- Less time to backup / restore
- Easier to maintain the SQL infrastructure if heavily used parts of the system need to be moved to a higher spec network segment
- Staging environments
- Publishing site collections can be used to stage content before using Content Deployment to move that content to the production site collection.
- Seperation of Information
- Relevant content can be organised in multiple Site Collections to keep the available content in context of a particular user. For example, IT based information may not be of interest to anyone outside of the department, so may be contained in it's own Site Collection.
What are the drawbacks of multiple Site Collections?
Whilst seperating your information out into logical segments has allt he benefits outlined above, there are a number of potential issues a system designer, developer or administrator may come across later in the project.
- Deploying Custom Features
Microsoft has designed the Site Collection to be, as far as we are concerned here, the most basic structure for the grouping of information in a SharePoint deployment (we will ignore the concepts of the Web Application and Farm here). This includes deploying Artifacts, sich as Content Types, Fields, List templates, etc. If we wish to deploy these common artifacts between multiple site collections then we need to do this each time for each site collection, so there is an additional administrative overhead that needs to be managed.
Serge Van Den Oever has a great blog article that outlines the scope available to different SharePoint Artifacts
- Rolling Up content across multiple Site Collections
Microsoft has provided a number of tools and solutions, as both webparts and API methods for searching multiple lists across a site collection. These include the Content Query Web Part and the SPQuery/SPSiteDataQuery methods.
Again, Microsoft intended the site collection to be the highest level container for our information so none of these tools or methods will work beyond the boundary of the site collection it is being run in.
There are a number of workarounds, mostly requiring custom rollup webparts that perform a query over multiple site collections and then aggregate the results, process them and display them. Another common solution is to use the SharePoint seach API / web parts to run a Enterprise search over multiple site collections and display out the results.
Dan Attis has an example of rolling up content from multiple site collections in this blog article.
- Running Workflow over multiple site collections
Workflows attatched to lists / document libraries only have context of the site collection they are being run in, so take a lot of custom code to manage workflow over multiple site collections.
- Navigating between site collections
Navigation is again controlled at the Site Collection level, so linking users between multiple site collections can be tricky and often requires custom code.