WGU D426 V2 Exam with accurate detailed ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
solutions
||//|\\||
The relationship (within the relation) that describes how the value of one attribute may be
||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
used to find the value of another attribute. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Functional Dependency ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
An attribute that can be used to find the value of another attribute in the relation.
||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Determinant
||//|\\|| ||//|\\|| ||//|\\||
Value can be used to find the value of every other non-key attribute in the table. Unique
||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
and minimal. ||//|\\||
Candidate Key ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Define & manage database structures ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
DDL
||//|\\|| ||//|\\|| ||//|\\||
Adding, deleting, and modifying data - Manipulates data stored in a database. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
DML
||//|\\|| ||//|\\|| ||//|\\||
Used to create user accounts, manage permissions and access. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
DCL
||//|\\|| ||//|\\|| ||//|\\||
Includes CREATE, DROP, ALTER, TRUNCATE, RENAME ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
DDL
||//|\\|| ||//|\\|| ||//|\\||
A view created and stored on the database. Underlying data is changed and also updated in
||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
this view. Uses memory space.
||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Materialized View ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Not stored in memory. Only computed when used or accessed.
||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
,Virtual View ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
The data about the data. Describes elements such as columns, names, and data type.
||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Metadata
||//|\\|| ||//|\\|| ||//|\\||
Ordered collection of elements in parentheses. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Tuple
||//|\\|| ||//|\\|| ||//|\\||
% of table rows selected by a query
||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Hit Ration ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Reads blocks directly, without accessing an index. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Table Scan ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Reads index blocks sequentially in order to locate the needed table blocks.||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Index Scan ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Database repeatedly splits the index in two until it finds a match. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Binary Search ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Database object that maps one or more tables to a single file. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Tablespace
||//|\\|| ||//|\\|| ||//|\\||
Specifies tables, columns, and keys. Implements database requirements in a specific ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
database system. Also called a schema. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Logical Design ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Specifies indexes, table structures, and partitions. Specifies how tables are organized on ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
storage media. ||//|\\||
Physical Design ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Components of a computer system and the relationships between components. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
, Architecture
||//|\\|| ||//|\\|| ||//|\\||
Interact directly with database users and administrators and send queries to the query ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
processor. Includes Connectors & APIs, Workbench, and utility programs. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Tools
||//|\\|| ||//|\\|| ||//|\\||
Interprets queries. Compiles queries into low-level instructions for the storage engine. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Creates a plan to modify the database or retrieve data, and returns query results to the ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
application.
Query Processor ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Link between tools and query processor ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Connection
||//|\\|| ||//|\\|| ||//|\\||
Creates connections and manages communication between tools and query parser. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Connection Manager ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Translates the query processor instructions into low-level file system commands that ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
modify or retrieve data. ||//|\\|| ||//|\\|| ||//|\\||
Storage Engine ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Accesses data on storage media. Data stored on storage media and organized in files. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Contains 3 types of data: - User data (tables & indexes) - Log files (record of any changes) - ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Data dictionary (aka: catalog directory of tables, columns, keys, indexes in a relational
||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
database). One row for each database object. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
File System ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Stores reusable information in main memory. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Cache Manager ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Retains data blocks from the file system for possible reuse. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Buffer Manager ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
solutions
||//|\\||
The relationship (within the relation) that describes how the value of one attribute may be
||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
used to find the value of another attribute. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Functional Dependency ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
An attribute that can be used to find the value of another attribute in the relation.
||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Determinant
||//|\\|| ||//|\\|| ||//|\\||
Value can be used to find the value of every other non-key attribute in the table. Unique
||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
and minimal. ||//|\\||
Candidate Key ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Define & manage database structures ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
DDL
||//|\\|| ||//|\\|| ||//|\\||
Adding, deleting, and modifying data - Manipulates data stored in a database. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
DML
||//|\\|| ||//|\\|| ||//|\\||
Used to create user accounts, manage permissions and access. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
DCL
||//|\\|| ||//|\\|| ||//|\\||
Includes CREATE, DROP, ALTER, TRUNCATE, RENAME ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
DDL
||//|\\|| ||//|\\|| ||//|\\||
A view created and stored on the database. Underlying data is changed and also updated in
||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
this view. Uses memory space.
||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Materialized View ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Not stored in memory. Only computed when used or accessed.
||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
,Virtual View ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
The data about the data. Describes elements such as columns, names, and data type.
||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Metadata
||//|\\|| ||//|\\|| ||//|\\||
Ordered collection of elements in parentheses. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Tuple
||//|\\|| ||//|\\|| ||//|\\||
% of table rows selected by a query
||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Hit Ration ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Reads blocks directly, without accessing an index. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Table Scan ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Reads index blocks sequentially in order to locate the needed table blocks.||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Index Scan ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Database repeatedly splits the index in two until it finds a match. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Binary Search ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Database object that maps one or more tables to a single file. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Tablespace
||//|\\|| ||//|\\|| ||//|\\||
Specifies tables, columns, and keys. Implements database requirements in a specific ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
database system. Also called a schema. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Logical Design ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Specifies indexes, table structures, and partitions. Specifies how tables are organized on ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
storage media. ||//|\\||
Physical Design ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Components of a computer system and the relationships between components. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
, Architecture
||//|\\|| ||//|\\|| ||//|\\||
Interact directly with database users and administrators and send queries to the query ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
processor. Includes Connectors & APIs, Workbench, and utility programs. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Tools
||//|\\|| ||//|\\|| ||//|\\||
Interprets queries. Compiles queries into low-level instructions for the storage engine. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Creates a plan to modify the database or retrieve data, and returns query results to the ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
application.
Query Processor ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Link between tools and query processor ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Connection
||//|\\|| ||//|\\|| ||//|\\||
Creates connections and manages communication between tools and query parser. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Connection Manager ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Translates the query processor instructions into low-level file system commands that ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
modify or retrieve data. ||//|\\|| ||//|\\|| ||//|\\||
Storage Engine ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Accesses data on storage media. Data stored on storage media and organized in files. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Contains 3 types of data: - User data (tables & indexes) - Log files (record of any changes) - ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Data dictionary (aka: catalog directory of tables, columns, keys, indexes in a relational
||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
database). One row for each database object. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
File System ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Stores reusable information in main memory. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Cache Manager ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
Retains data blocks from the file system for possible reuse. ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\|| ||//|\\||
Buffer Manager ||//|\\||
||//|\\|| ||//|\\|| ||//|\\||
