How SQL Engine Database Works

We now assume that you know what SQL is, or have experience with SQL, or have used it for years. We know many people who know a lot about SQL and have even done many projects with SQL but do not know what an SQL engine or SQL engine is or how a SQL database engine works.

Obviously, few people care about the internal workings of the SQL engine because we can create and access a database using any SQL application without knowing how SQL works.

Is SQL a programming language or a query language?

With SQL we can exchange programming and query language, many developers look at SQL as a separate programming language because the SQL engine consists of two components: the compiler and the virtual machine, which is the compiler. Compiles query commands to procedures and executes processors' virtual machines. The concept of compiling and executing SQL queries by the SQL engine makes it a programming language. So if someone says SQL is a programming language, they are somewhat right.

Why use SQL for any programming language that can create CRUD operations?

It is true that with any programming language we can perform simple CRUD operations (Create, Read, Update and Delete), but when the program is accompanied by complex queries in the programming language we have to write hundreds of lines equivalent to several short SQL lines.

Overview of SQL

SQL stands for Structured Query Language, which can be considered as a programming or query language. Its main purpose is to interact with a relational database in which data is stored in tables. SQL can handle large volumes of data, especially if the data is written at the same time and we have a lot of data transfer.

When a user uses SQL to manage data, he or she can perform data creation, retrieval, update, and deletion. There are a variety of relational database management systems (DBMS), such as MySQL, SQLite, Postgres SQL, etc., and they all offer the same type of attribute.

What is SQL Engine?

The SQL engine is a type of software that compiles and interprets SQL statements, so proper operations can be performed on the relational database. The purpose of the SQL engine is to create, read, update, and delete (CRUD) data from the database.

A SQL engine or SQL server database engine consists of two main components: a storage engine and a query processor. Some modern SQL DBMSs today include more than one type of storage engine. We have different types of SQL engines, and they all have different architectures, but they are used for the same purpose, which includes CRUD operations on the database and many other features.

SQL covers a large part of the online marketplace, and many companies use their SQL systems for online transaction processing and online analytics processing.

How does SQL Database Engine work?

We know that the SQL compiler compiles the query and executes the compiled query virtual machine. Now let's see how the database engine works.

SQL has many steps that make the query compilation process and execution. As we said, every SQL database engine consists of two main components, the compiler and the virtual machine. The compiler reads the query and converts this query to the appropriate bytecode, then the bytecode is evaluated by the virtual machine and returns the appropriate response to the client.

Complete query execution consists of 4 main steps:

1. Compile (parsing, reviewing)  

2. Binding (connection)  

3. Optimization  

4. Execution  


This is part of the compilation process, and at this point the query command is tokenized with the appropriate components in unique expressions.


This section validates the command and matches it to the system directory. This compilation step validates whether the query is valid or not, and also validates the user permission to execute this command.


Creates the corresponding binary representation for the entered query command. All SQL server engines have this stage of compilation in which byte code is generated.

Using this step, the command is compiled and now sent to the database server for optimization and execution.


At this point the best algorithm for the bytecode is optimized. This feature is also known as Query Optimizer or Relational Engine.


The virtual machine receives the optimized bytecode and executes it.

Note: The compile parsing process does not require any database permissions, which makes this the fastest step in the compilation process.

Convert SQL from data to table

SQL is written in C and uses the Binary-Tree principle, which allows input data to be stored in rows and columns. There are several branches in the Binary-Tree structure that point to a new data element, and this structure is followed by the SQL database, which converts the data into tables where each column and row of data point to each other.

What is a SQL Server Storage Engine?

It is software used to perform CRUD operations between disk and memory.


To create a database environment, we need a SQL database engine, and low-level programming languages such as C or C ++ are often used to build the database engine because they give the user control over memory management, which exists in high-level programming. does not have. In high-level languages, memory management is done automatically by the operating system. SQL engine is a cross-platform development and can use different platforms to build some applications, but all platforms can link to SQL engine for database features.

Sql Server

What is sql engine how does sql engine work how does sql server work what is sql engine query execution process what does sql engine do programming query language query compilation process database architecture database design
You must be logged in to post a comment