Introduction To Databases Flashcards
Data
Data is numeric, textual, visual, or audio information that describes real-world systems
Analog
historically, data was mostly analog, encoded as continuous variations or various physical media
Digital
Digitally encoded as zeros, and ones on electronic and magnetic media
Database
Collection of data in a structured format.
Database System, Database management system, DBMS
Software that reads and writes data in a database. Database systems ensure data is secure, internally consistent, and available at all times.
Query Language
Specialized programming language, designed specifically for database systems
Database application
Software that helps business users interact with database systems.
Database administrator
Database admin is responsible for securing the database system against unauthorized users. DB admin also enforces procedures for user access and database system availability.
database designer
Determines format of each data element and overall database structure. DB Designer must balance several priorities, including storage, response time, and support for rules that govern the data.
Database Programmer
Database programmer develops computer programs that utilize a database
Database User
Consumer of data in a database. Database users request, update or use stored data to generate reports or information.
Transacation
Group of queries that must be either completed or rejected as a whole.
Architecture
Architecture of a database system describes the internal components and the relationships between components
Query Processor
Query processor interprets queries, creates a plan to modify the database or retrieve data, and return’s query results to the application.
Query Optimization
Query processor performs query optimization to ensure the most efficient instructions are executed on the data
Storage manager
Translate the query processor instructions into low-level-file-system commands that modify or retrieve data
Indexes
Storage Manager uses indexes to quickly locate data
Transaction Manager
Transaction manager ensure transactions are properly executed
Log
Log file containing a complete record of all inserts’, updates, and delete processed by the database.
Catalog/Data dictionary
Dictionary of tables, columns, indexes, and other database objects
Relational Database
Stores data in tables, columns, and rows, similar to a spreadsheet
SQL
Structured Query Language and includes statements that read and write data, create and delete tables, and administer the database system
Big Data
Growth of the internet generated massive volumes of online data, often with poorly structured or missing information.
NoSQL
Newer, non-relational systems are called NOSQL, for Not Only SQL, and are optimized for big data.
Open Source
Software that anyone can inspect, copy, and modify with no licensing fee.
Query
Command for a database that typically inserts new data, retrieves data, updates data, or deletes data from a database
Query Language
Computer programming language for writing database queries
CRUD
Four Common queries sometimes referred to as CRUD operations, acronym for Create, Read, Update, and Delete data
Statement
SQL statement is a database command, such as a query that inserts, selects, updates, or deletes data
Insert
Inserst rows into a tables
Select
Retrieves data from a table
Update
Modifies data in a table
Delete
Deletes rows in a table
Create Table
Statement creates a new table by specifying the table and column names
Data Type
Every column is assigned a datatype that indicates the format of column values. Data type can be numeri, Textual, or complex
Database Design
Specification of database objects such as tables, columns, data types, and indexes. Database design also refers to the process used to develop the specification
Analysis
Analysis phase specifies database requirements without regard to a specific database system
ER Diagrams
Entities, relationships, and attributes are depicted in ER diagrams.
Logical design
Phase that implements database requirements in a specific database system
Key
Key is a column used to identify individual rows of a table
Table Diagram
Logical design is depicted in a table Diagram