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WGU D426 EXAM : OBJECTIVE ASSESSMENT
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WGU D426 EXAM : OBJECTIVE ASSESSMENT
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WGU D426 EXAM : OBJECTIVE ASSESSMENTSoftware that helps business users interact with database systems. - answer- Database
Application
Responsible for securing the database system against unauthorized users. A database administrator enforces procedures for user access and database system availability. - answer- Database Administrator
Many database users should have limited access to specific tables, columns, or rows of a database. Database systems authorize individual users to access specific data. - answer- Authorization
Database systems ensure data is consistent with structural and business rules. - answer- Rules
Interprets queries, creates a plan to modify the database or retrieve data, and returns query results to the application. Performs query optimization to ensure the most efficient
instructions are executed on the data. - answer- Query Processor
Translates the query processor instructions into low-level file-system commands that modify or retrieve data. Database sizes range from megabytes to many terabytes, so the storage manager uses indexes to quickly locate data. - answer- Storage Manager
Ensures transactions are properly executed. The transaction manager prevents conflicts
between concurrent transactions. The transaction manager also restores the database to a consistent state in the event of a transaction or system failure. - answer- Transaction Manager
Data about the database, such as column names and the number of rows in each table.
- answer- Metadata
Is an unnamed tuple of values. Each value corresponds to a column and belongs to the column's data type. - answer- Row
A ____ _____ is a named set of values, from which column values are drawn. - answer-
Data Type
Selects all rows of two tables. - answer- Union
Computes functions over multiple table rows, such as sum and count. - answer- Aggregate
Rules that are logical constraints and ensure data is valid. - answer- Relational Rules SQL is the standard language for relational databases, and is commonly supported in non-relational databases. - answer- The standard language for Relational Databases...
Explicit values that are string, numeric, or binary.Strings must be surrounded by single quotes or double quotes.Binary values are represented with x'0' where the 0 is any hex value. - answer- Literals (SQL Syntax)
Words with special meaning.
ex. SELECT, FROM, WHERE - answer- Keywords (SQL Syntax)
Objects from the database like tables, columns, etc.
ex. City, Name, Population - answer- Identifiers (SQL Syntax)
Data Definition Language (DDL) defines the structure of the database.
Data Query Language (DQL) retrieves data from the database.
Data Manipulation Language (DML) manipulates data stored in a database.
Data Control Language (DCL) controls database user access.
Data Transaction Language (DTL) manages database transactions. - answer- SQL Sublanguages
A single column of a single row. - answer- Cell
Rows - answer- Not Ordered
Rule 7. Allows database administrators to improve query performance by changing the organization of data on storage devices, without affecting query results. - answer- Data Independence
Statement that deletes a table, along with all the table's rows, from a database. - answer- DROP TABLE
Statement that adds, deletes, or modifies columns on an existing table. - answer- ALTER TABLE
4 bytes - answer- INT
2 bytes - answer- SMALLINT
8 bytes - answer- BIGINT
1 byte - answer- TINYINT
3 bytes - answer- MEDIUMINT
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