Sql Overview Flashcards
What is SQL?
Structured query language (SQL) is a programming language for storing and processing information in a relational database.
Why is SQL important?
SQL is frequently used in all types of applications, integrates well with different programming languages, and is easy to learn.
What was SQL originally known as?
Structured English Query Language (SEQUEL).
Who was the first vendor to offer a commercial SQL relational database management system?
Oracle, formerly known as Relational Software.
What is a SQL table?
The basic element of a relational database consisting of rows and columns.
What are SQL statements?
Valid instructions that relational database management systems understand.
What is a stored procedure?
A collection of one or more SQL statements stored in the relational database to improve efficiency and performance.
What is the role of the parser in SQL?
The parser tokenizes SQL statements, checks for correctness, and validates user authorization.
What does the relational engine do?
Creates a plan for retrieving, writing, or updating data efficiently.
What is a storage engine?
The software component that processes byte code and runs the intended SQL statement.
What are the categories of SQL commands?
Data Definition Language (DDL), Data Query Language (DQL), Data Manipulation Language (DML), Data Control Language (DCL), Transaction Control Language (TCL).
What does Data Definition Language (DDL) do?
Designs the database structure and creates or modifies database objects.
What is the purpose of Data Query Language (DQL)?
Retrieves data stored in relational databases.
What does Data Manipulation Language (DML) do?
Writes new information or modifies existing records in a relational database.
What is the function of Data Control Language (DCL)?
Manages or authorizes database access for other users.
