WGU D322 Section 6

database management system

converts large amounts of data into a usable format to help users make business decisions

multidimensional

Most databases—for example, relational databases—are _______, allowing information to be accessed from various views through internal linking between entries

traditional flat file systems

one-dimensional; present information from a single point of view and do not interact with other files

database research

the act of analyzing and converting data into information that can be used in decision-making

application layer

layer of a database that does not directly manipulate the data; communicates with the end user and can be fairly complex

database management system (DBMS)

if the request is to add or delete data to or from the system; if the request is to retrieve information; similar to an operating system in that it supports the application software and the data

flat-file database

stores data in a plain text file; each line of the text file holds one record; cannot contain multiple tables

hierarchical database

organized in a tree structure; There is one parent for each record, with optional nodes, forming sub-trees called segments. Access to the data is predictable and restricted to the paths in the trees.

relational databases

contain database tables that can be joined together in logical ways; each record has a unique identifier called the primary key

foreign key

field that may be marked as the primary key on one table but also be found on another table

Structured query language (SQL)

code that includes queries to identify what data should be retrieved or how the data should be manipulated

selection operation

takes rows from one table and creates a new table

union operation

combines distinct fields from multiple tables that have the same set of attributes and data types

product operation

creates a result table that includes all of the attributes from the two tables; each row of the second table is added to each row of the first table

join operation

combines two tables, but records are only appended when a matching criterion is met. The result table includes a row with the attributes of both tables only when attributes from the first database table match related attributes from the second database table

implicit joint

SELECT*

FROM Patient, Nurse;

explicit joint

SELECT*

FROM Patient CROSS JOIN Nurse;

object-oriented (OO) databases

store complex data and relationships between data directly without using inter-table relations; a collection of objects, each with two components: data and instructions

NoSQL

databases geared towards managing large sets of varied and frequently updated data; avoid the rigid schemas associated w/ relational databases; separated into four primary classifications

Document databases (NoSQL)

store data elements in document-like structures that encode information in formats

Graph databases (NoSQL)

emphasize connections between data elements, storing related "nodes" into graphs to accelerate querying

Key-Value stores (NoSQL)

use a simple data model that pairs a unique key and it's associated value in storing data elements

Wide-Column stores (NoSQL)

also called table-style databases; they store data across tables that can have very large numbers of columns

Cloud databases

Optimized to work in a cloud environment. Some practical benefits include the ability to increase resources to accommodate for demands on the system, to be highly available even in the case of local or regional outages, and to support SaaS (software as a service) cloud deployments

data lake

system of data stored in raw format; can include both structured data, such as tables, and unstructured data, such as audio and video recordings

distributed database

consists of data residing on different machines

scalability

the ability to accommodate increased demands while using existing resources

Database security

ensuring that only authorized users have access to the database and fortifying it against unauthorized access

Database tuning

optimizing performance of database systems

High availability

making replicas of databases available from various locations; if one copy is unavailable due to outage, the alternate location can continue database services

Business continuity

continuing core business operations effectively, even with the disruption of some auxiliary services

Backup and recovery

planning for and executing adequate backup and recovery procedures

Reporting

writing complex queries and generating reports for users

Designing and developing database applications

writing code to interact with the database resources

Data and business intelligence

Which data management tool deals with analyzing specific categories of historical information and making decisions based on that information?