SQL SERVER Relational and Storage Engine
SQL SERVER Relational and Storage Engine
There are a lot of factor to keep in mind when building databases in SQL Server. The context for understanding those factors begins with a fundamental fact about SQL Server architecture, namely that at its core, SQL Server consists of two independent subsystems, the relational engine (or query engine) and the storage engine.
The relational engine processes queries, whereas the storage engine stores and retrieves data. The relational engine communicates with the storage engine via the low level OLE DB.
The relational engine processes two fundamental types of queries: data definition (DDL) and data manipulation (DML). You use DDL commands to define the databases, tables, indexes, and constraints that make up your application’s data source. For example, CREATE TABLE, CREATE INDEX, and so on are DDL commands. You use DML commands to manipulate data and populate tables with data. SELECT, INSERT, UPDATE and DELETE are DML command.
Whenever you communicate with SQL Server storage engine, you use the Transact SQL language, the dialect of SQL that belongs to SQL Server. Let’s take a closer look at the relationship of the relational engine. Transact SQL and the SQL language.
Relational database system, widely used nowadays, is first formulated by E.F. Codd, an IBM mathematician. He based his ideas on the application of set theory to data structure. A few prototype relational database systems are introduced in the early 1980s. since that time, the relational DBMS has become the dominant method for storing database data.
The relational model of database storage is a well developed theory of how data should be stored and manipulated. If you store data in the relational format and if you follow the relational model’s rules, then the results of performing relational operations on the data can be predicted with mathematical certainty.
Written by,
Kasim Wirama, MCSD.NET, MCDBA.
Database Administrator