SQL Server is a database management system, or RDBMS, developed and sold by Microsoft. Similar to other RDBMS software, SQL Server is built on top of SQL, a standard programming language for interacting with databases.
SQL Server comes bundled with Transact-SQL or T-SQL, the latter being Microsoft's SQL which adds a proprietary set of programming constructs.
SQL Server has worked exclusively in the Windows environment for over 20 years. In 2016, Microsoft debuted a Linux version of SQL Server. SQL Server 2017 was generally released in October 2016 and runs on Windows and Linux.
SQL Server consists of two main components:
- Database Engine
- SQLOS database engine
Database engine is one of the core components of SQL Server. It consists of a relational engine that handles queries as well as a storage engine that aims to manage database files, pages, indexes, etc. The database engine also creates and executes database objects such as stored procedures, views, and triggers.
When it comes to a relational engine, it has components which direct the best way to perform a query (known as query processor). It requests data from the storage engine formed on the input query and processes the results. Some of the tasks of a relational engine include query processing, memory management, thread and task management, buffer management, and distributed query processing.
Storage engines are responsible for storing and retrieving data from storage systems such as disks and SANs.
The last SQL Server operating system is Server operating system, or SQLOS. It provides a lot of operating system services, for example, memory and I/O management, exception handling and synchronization services.
SQL Server can meet different types of database solutions required by today's business environment. It is a widely used database management system with many significant advantages: ease of use, scalability suitable for distributed organizations, data warehouse functions for decision support, integration with many other server software, good cost performance etc. Performance, scalability, and reliability are key functions.
In addition to these SQL Server advantages, SQL Server also brings flexibility to your data management and analysis, allowing organizations to respond quickly in a rapidly changing environment, thereby gaining a competitive advantage.
Advantages of SQL Server
1. CLR (Common Language Runtime)
The major enhancement in SQL Server is the integration of languages that conform to the .NET specification, such as C#, ASP.NET or VB.NET that can build objects (stored procedures, triggers, functions, etc.). This allows you to execute .NET code in the database management system to take full advantage of .NET functionality. It is expected to replace extended stored procedures in a SQL Server 2000 environment while also extending the capabilities of traditional relational engines.
2. Enhanced T-SQL (transactional SQL)
T-SQL is a set-based relational database management system programming language that provides high-performance data access. It has with many new features, including error handling by using both TRY and CTACH, Common Table Expressions (CTEs) that return a result set in the statement, and the ability to turn columns into rows.
3. Service Broker
A service broker handles messages between senders and receivers that are loosely connected. A message is sent, processed and answered, completing the entire transaction. This greatly extends the performance of data-driven applications to match the workflow of customer business needs.
4. HTTP terminal
You can easily create an HTTP endpoint by making an object accessible over the Internet with a simple T-SQL statement. This allows a simple object to be called from the Internet to fetch the required data.
5. Dedicated administrator connection
This feature allows database administrators to initiate a single diagnostic connection to SQL Server, even if the server is experiencing problems.
6. Multiple Active Result Sets (MARS for short)
Multiple Active Result Sets allow a persistent connection from a single client to the database to have more than one active request per connection. This is a major performance improvement and allows developers to give users new capabilities when working with SQL Server. For example, it allows multiple queries, or simultaneous input of data for one query.
7. SQL Server Integrated Services (SSIS)
SSIS has replaced DTS (Data Transfer Services) as the main ETL (Extract, Transfer and Load) job, and it comes with SQL Server. This tool, completely rewritten starting with SQL Server 2000, now has a great degree of flexibility to meet complex data movement needs.