Identify the missing word(s) in the following sentence within the context of Microsoft Azure. When creating a database, SQL Server maps this database with minimum two operating system files; the database data file MDF and the database log file LDF. Logically, the database data files are created under a collection set of files that simplifies the database administration. The SQL Server component that is responsible for managing the data storage within the database files, called the SQL Server [?]. It uses a fill mechanism that writes data to the database files depending on the amount of free space in each data file rather than writing in each file until it is full then moving to the second one sequentially. This data filling algorithm is called Proportional Fill Algorithm.