Do i have to store Sharepoint content in SQL Server?
One frequently asked question is if SQL Server is the only option to store content in a sharepoint environment. The confustion stems from the fact that SQL Server is a requirement for installing sharepoint.
The answer is, there is no necessity to store your content in SQL Server. The content can be stored external to the sharepoint environment. This is referred to as external content stores and then you can configure sharepoint to index this content so it can be searched against. Here is a link that explains this clearly:
https://www.microsoft.com/technet/windowsserver/sharepoint/V2/reskit/c2261881x.mspx
The reason SQL Server is a requirement for installing sharepoint even if you decide to store your content external to SQL Server is because SQL Server is used by Sharepoint to store metadata that it needs. While content can be stored in external content stores as documented above, it is a good idea to bring all your content into the sharepoint environment if possible. The following is an excellent article that talks about the migration process and the guidelines and tools required to do this: