Introduction to Databases

Vocabulary from chapter 1

Data

numeric, textual, visual, or audio information that describes real-world systems

scope, format, and access

Data varies in

Database

a collection of data in a structured format

Database system

a software that reads and writes data in a database

Query

a request to change or retrieve data in a databaseQ

uery language

a specialized programming language designed specifically for database systems

Information management system

a software application that manages corporate data for a specific business function

Database administrator

responsible for securing the database system against unauthorized users

Database designer

determines the format of each data element and the overall database structure

Database programmer

develops computer programs that utilize a database

Database user

a consumer of data in a database

performance, authorization, security, rules, recovery

requirements of large, complex databases

Transaction

a group of queries that must be either completed or rejected as a whole

database systems must

ensure transactions are processed completely or not at all, prevent conflicts between concurrent transactions, and ensure transaction results are never lost

architecture

describes the internal components and the relationship between components

quenry processor

interprets queries, creates a plan to modify the database or retrieve the data, and returns the query results to the application

query optimization

ensures the most efficient instructions are executed on the data

storage manager

translates the query processor instructions into low-level file-system commands that modify or retrieve data

indexes

used to quickly locate data

transaction manager

ensures transactions are properly executed by preventing conflicts between concurrent transactions

log

a file for containing a completed record of all inserts, updates, and deletes processed by the database

catalog or data dictionary

a directory of tables, columns, indexes, and other database objects

structured query language (SQL)

includes statements that read and write data, create and delete tables, and administer the database system

big data

a large volume of online data from the 1900s, often poorly structured or missing information

NoSQL

newer non-relational systems optimized for big data

open source

software that anyone can inspect, copy, and modify with no licensing fee

SQL statement

a complete, executable database command

CREATE TABLE

a statement that creates a new table by specifying the table and column names

data type

indicates format of column values

INT

integer SQL data type

DECIMAL

fractional numeric values SQL data type

VARCHAR

textual values SQL data type

DATE

year, month, and day SQL data type

DATETIME

date and time SQL data type

database design

a specification of database objects such as tables, columns, data types, and indexes

conceptual designER

a design phase that specifies database requirements without regard to a specific database system

ER diagrams

depict entities, relationships, and attributes

logical design

a design phase that implements database requirements in a specific database system

physical design

a design phase that adds indexes and specifies how tables are organized on storage media

data independence

the principle that physical design never affects query results

application programming interface (API)

a library of procedures or classes that links a host programming language to a database

MySQL

a leading relational database system sponsored by Oracle

database model

a conceptual framework for database systems with data structures, operations, and rules

relational model

a database model based on tabular data structure

set

an unordered collection of elements enclosed in {braces}

tuple

an ordered collection of elements enclosed in (parenthases)

relational algebra

a collection of operations that are the theoretical foundation of the SQL language

relational rules

a part of the relational model and govern data in every relational database

business rules

based on the business policy and specific to a particular database

SQL constraints

relational rules enforced by the database system