Data Management - Foundations - D426 WGU questions with answers

Data Management - Foundations - D426 WGU
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questions with answers |\ |\




Data

numeric , textual , visual or audio information that describes real-world
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systems.
varies in ways such as scope, format, access.
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analog data |\




Historically most common before computers, encoded as continuous
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variations on various physical media.|\ |\ |\ |\




digital data |\




most common today, recorded as 0's and 1's on electronic and magnetic
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media.

database designer |\




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

database user |\




a consumer of data in a database. can either use an application or submit
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queries directly to the database. they use, request and update data. to
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generate reports |\




transaction

a group of queries that must be completed or rejected as whole. will result in
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incomplete or incorrect data if not terminated as a whole.
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Query processor |\

,interprets queries, creates a plan to modify the database or retrieve data, and
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returns query results to the application.
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Query optimization |\




to ensure the most efficient instructions are executed on the data from the
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processor.

Storage Manager |\




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




indexes

used by the storage manager to quickly locate data
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catalog

also called a data dictionary , a directory of tables, columns and indexes as
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well as other database objects.
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relational database |\




a database that stores data in tables that consist of rows and columns,
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similar to a spreadsheet |\ |\ |\




SQL

Structured Query Language |\ |\




NoSQL

A new generation of database management systems that is not based on the
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traditional relational database model. |\ |\ |\




query

command for a database that typically inserts, retrieves, updates and deletes
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data from the database.
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crud

, Create, Read, Update, Delete
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statement

a database command such as a query that inserts , selects updates and
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deletes data |\




SELECT

Retrieves data from a table|\ |\ |\ |\




UPDATE

modifies data in a table
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data type |\




indicates the type of data that can be stored in a field of a column
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data independence
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A condition in which data access is unaffected by changes in the physical
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data storage characteristics.
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database model |\




Describes the relationship between the data elements and provides a
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framework for organizing the data. contains 3 parts
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data structures
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operations
rules

relational model |\




A database model that describes data in which all data elements are placed
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in two-dimensional tables, called relations, which are the logical equivalent
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of files.
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row