Chapter 1: Introduction - Fundamentals of Database Systems

Vocabulary flashcards covering core database concepts, data models, levels of abstraction, database languages, query processing, storage and transaction management, architectures, and history.

Database Management System (DBMS)

A system containing information about a particular enterprise, composed of a collection of interrelated data and a set of programs to access the data in a convenient and efficient environment.

Data Models

A collection of conceptual tools for describing data, data relationships, data semantics, and consistency constraints.

Relational Model

A data model where all data is stored in various tables consisting of rows and columns, introduced by Ted Codd.

Physical Level

The lowest level of data abstraction that describes how a record (e.g., instructor) is stored in the database.

Logical Level

The level of data abstraction that describes what data are stored in the database, and the relationships among those data.

View Level

The highest level of data abstraction where application programs hide details of data types and can hide information for security purposes.

Logical Schema

The overall logical structure of the database, analogous to type information of a variable in a programming language.

Physical Schema

The overall physical structure of the database.

Instance

The actual content of the database at a particular point in time, analogous to the value of a variable in a programming language.

Physical Data Independence

The ability to modify the physical schema without changing the logical schema.

Data Definition Language (DDL)

Specification notation for defining the database schema.

Data Dictionary

A structure generated by the DDL compiler containing metadata (data about data), such as database schema, integrity constraints, primary key definitions, and authorization.

Data Manipulation Language (DML)

Language for accessing and updating the data organized by the appropriate data model; also known as query language.

Procedural DML

A type of data-manipulation language that requires a user to specify what data are needed and how to get those data.

Declarative DML

A non-procedural data-manipulation language that requires a user to specify what data are needed without specifying how to get those data.

SQL Query Language

A non-procedural query language where a query takes as input several tables (possibly only one) and always returns a single table.

Application Programs

Programs written in host languages (such as C/C++, Java, or Python) with embedded SQL queries that are used to interact with the database.

Logical Design

The phase of database design focused on deciding on the database schema and finding a good collection of relation schemas.

Physical Design

The phase of database design focused on deciding on the physical layout of the database.

Storage Manager

A program module that provides the interface between the low-level data stored in the database and the application programs and queries submitted to the system.

Indices

Data structures implemented by the storage manager that provide fast access to data items by providing pointers to items holding a particular value.

DDL Interpreter

A query processor component that interprets DDL statements and records the definitions in the data dictionary.

DML Compiler

A query processor component that translates DML statements in a query language into an evaluation plan consisting of low-level instructions and performs query optimization.

Query Evaluation Engine

A query processor component that executes low-level instructions generated by the DML compiler.

Transaction

A collection of operations that performs a single logical function in a database application.

Transaction-management Component

A database engine component that ensures the database remains in a consistent (correct) state despite system failures and transaction failures.

Concurrency-control Manager

A component that controls the interaction among concurrent transactions to ensure the consistency of the database.

Two-tier Architecture

An architecture where the application resides at the client machine and invokes database system functionality at the server machine.

Three-tier Architecture

An architecture where the client machine acts as a front end without direct database calls, communicating with an application server which then communicates with a database system.

Database Administrator (DBA)

A person who has central control over the database system, responsible for schema definition, storage structure definition, authorization, disk space management, and routine maintenance.

Ted Codd

Computer scientist who defined the relational data model in the late 1960s and 1970s and won the ACM Turing Award in 1981.

Database System Levels of Abstraction Architecture

An architectural view showing the physical level at the bottom, the logical level in the middle, and multiple user view levels at the top.

Query Processing Workflow

The sequential flow of processing a database query through parsing and translation, optimization into an execution plan, and evaluation by the execution engine.

Two-tier and Three-tier Architectures Diagram

A structural diagram contrasting two-tier client-server application architecture with three-tier client/application-server/database-system architecture.