Microsoft SQL Server is Microsoft’s relational database management system offering. Primarily, it utilizes Transact-SQL as its query language. Its architecture is divided into three separate components.
It needs SQLOS as its base component in the architecture. SQL Server has special requirements so SQLOS does what normally an ordinary OS would do. It does its own memory management, thread scheduling and buffer pool management. It also functions to manage its own I/O, synchronization primitives and locking, deadlock detection and its resources. Since SQLOS manages its memory requirement, it is basically concerned with reducing disc I/O.
The Relational engine, on the other hand, executes the functionalities of the SQLOS. It works to implement the data type and it defines what types of data will be stored in the tables. It also identifies various types of data that it is able to store. The Relational engine also includes a storage engine which implements how data is to be stored in the persistent storage devices. It also provides a means for faster data access.
And finally, the protocol layer would do its part by implementing the outer layer of the interface. All operations possible for SQL Server are communicated to it using the Tabular Data Stream.
For companies who require SQL Server to be hosted, they will have many options because there are quite many SQL Server hosting providers. There are providers who actually offer their services at competitive prices. Of course, the better SQL Server hosting provider would be the one who can manage the company databases well. It is also important that systems are always up and there are minimal downtimes.