DAD 220 NEW COMBINED STUDY SET EXAMS WITH COMPLETE SOLUTIONS 100%
VERIFIED9 (DAD-220 Test Exam,DAD220 Ch 3,SNHU DAD 220,DAD 220 - 3-1 quiz &
DAD 220 - Introduction to Course)
-DAD-220 Test Exam
-DAD220 Ch 3
-SNHU DAD 220
-DAD 220 - 3-1 quiz
-DAD 220 - Introduction to Course
DAD-220 Test Exam
Data
raw information, collected raw facts and values - stock prices
Types of data formats
text, image, audio, video
Types of data sources
industries, governments, individuals, and more
Information
data that has been processed and analyzed to give the facts more value and meaning - a
graph of stock prices over time
common sources of data - Social Networks
Facebook, twitter, youtube, blogs, search engines, etc
,common sources of data - business systems
medical records, commercial transactions, bank records, e-commerce
Common sources of data IoT
Home automation, weather sensors, traffic sensors, webcams, surveillance videos,
security images
Data.gov
USA government geoportal to search for USA federal executive branch datasets
provides over 250,000 US government data sets for research and development of
applications
NASA's Data Portal
provides several data sets related to aeronautics, Earth sciences and space sciences
Resources
The computer hardware CPU, memory, storage space and software components that
are available to the database system. To manage Verify sufficient resources exist and
run database performance analysis tools to test performance relative to hardware,
software and end user application usage.
Data Contention
When several users and applications are competing to use the same data. To regulate,
A database system can be designed in a way to pre-emptively limit data contention.
transaction
A transaction occurs when data is altered in some fashion within a database
,management system. The database management system should guarantee a
transaction operates correctly. Two methodologies used to support transactions are the
ACID properties and concurrency.
Atomicity
Ensures a transaction runs successfully to the end otherwise the transaction is not
executed at all. If one data change in the transaction is not successful then none of the
data changes are made to the database
Consistency
Refers to whether or not changes to a database are valid based on the design of the
database. EX: consistency ensure non-numeric data cannot be used to update numeric
data, and a customer cannot be deleted from one part of the database without also
deleting the customers data in other parts
Isolation
allows multiple transactions to change shared data simultaneously without corrupting it.
EX: if transaction 1 deleted user "rsmith" from a table and transaction 2 simultaneously
tried to update data about rsmith, transaction 1s deletion of rsmith would be reverted
and transaction 2 would go through
durability
successful transactions are written to a file system. data saved in permanent format is
called PERSISTENCE. Persistence ensures that in case of failure of a computer system,
data will not be lost.
Concurrency
It allows multiple users to share the database for reading and writing simultaneously.
Database Components
There are 3 major components in a database system.
1. Query Processor
2. Storage Manager
, 3. Transaction Manager
Query Processor
it interprets queries, creates a strategy to modify the database or to retrieve data from
the database and returns query results back to the requesting application.
### Query optimization
How a database system determines the most efficient way to execute a query. To
manage, A database system generates query plans (set of steps to access data) to aid
optimization. A trade-off exists between spending a lot of time generating an optimal
plan and getting the best results.
Storage Manager
authorises database access and interacts with the file system. It translates the
instructions from the query processor into low level file system commands to modify or
retrieve the database data. It manages data dictionary. databases can range from
several megabytes to several terabytes so the storage manager uses an index to quickly
locate data.
Data Dictionary
stores information about the structure of the database and the types of data in the
database.
Transaction Manager
ensures transactions are ACID compliant, can manage concurrency through the
placement of locks on data, and can handle transaction failure. It keeps a log of all
transaction performed by the database system. In case of failure, the database can
rebuild itself from that log.
Database architecture
Database applications can be partitioned into one, two, or three parts or "tiers"
VERIFIED9 (DAD-220 Test Exam,DAD220 Ch 3,SNHU DAD 220,DAD 220 - 3-1 quiz &
DAD 220 - Introduction to Course)
-DAD-220 Test Exam
-DAD220 Ch 3
-SNHU DAD 220
-DAD 220 - 3-1 quiz
-DAD 220 - Introduction to Course
DAD-220 Test Exam
Data
raw information, collected raw facts and values - stock prices
Types of data formats
text, image, audio, video
Types of data sources
industries, governments, individuals, and more
Information
data that has been processed and analyzed to give the facts more value and meaning - a
graph of stock prices over time
common sources of data - Social Networks
Facebook, twitter, youtube, blogs, search engines, etc
,common sources of data - business systems
medical records, commercial transactions, bank records, e-commerce
Common sources of data IoT
Home automation, weather sensors, traffic sensors, webcams, surveillance videos,
security images
Data.gov
USA government geoportal to search for USA federal executive branch datasets
provides over 250,000 US government data sets for research and development of
applications
NASA's Data Portal
provides several data sets related to aeronautics, Earth sciences and space sciences
Resources
The computer hardware CPU, memory, storage space and software components that
are available to the database system. To manage Verify sufficient resources exist and
run database performance analysis tools to test performance relative to hardware,
software and end user application usage.
Data Contention
When several users and applications are competing to use the same data. To regulate,
A database system can be designed in a way to pre-emptively limit data contention.
transaction
A transaction occurs when data is altered in some fashion within a database
,management system. The database management system should guarantee a
transaction operates correctly. Two methodologies used to support transactions are the
ACID properties and concurrency.
Atomicity
Ensures a transaction runs successfully to the end otherwise the transaction is not
executed at all. If one data change in the transaction is not successful then none of the
data changes are made to the database
Consistency
Refers to whether or not changes to a database are valid based on the design of the
database. EX: consistency ensure non-numeric data cannot be used to update numeric
data, and a customer cannot be deleted from one part of the database without also
deleting the customers data in other parts
Isolation
allows multiple transactions to change shared data simultaneously without corrupting it.
EX: if transaction 1 deleted user "rsmith" from a table and transaction 2 simultaneously
tried to update data about rsmith, transaction 1s deletion of rsmith would be reverted
and transaction 2 would go through
durability
successful transactions are written to a file system. data saved in permanent format is
called PERSISTENCE. Persistence ensures that in case of failure of a computer system,
data will not be lost.
Concurrency
It allows multiple users to share the database for reading and writing simultaneously.
Database Components
There are 3 major components in a database system.
1. Query Processor
2. Storage Manager
, 3. Transaction Manager
Query Processor
it interprets queries, creates a strategy to modify the database or to retrieve data from
the database and returns query results back to the requesting application.
### Query optimization
How a database system determines the most efficient way to execute a query. To
manage, A database system generates query plans (set of steps to access data) to aid
optimization. A trade-off exists between spending a lot of time generating an optimal
plan and getting the best results.
Storage Manager
authorises database access and interacts with the file system. It translates the
instructions from the query processor into low level file system commands to modify or
retrieve the database data. It manages data dictionary. databases can range from
several megabytes to several terabytes so the storage manager uses an index to quickly
locate data.
Data Dictionary
stores information about the structure of the database and the types of data in the
database.
Transaction Manager
ensures transactions are ACID compliant, can manage concurrency through the
placement of locks on data, and can handle transaction failure. It keeps a log of all
transaction performed by the database system. In case of failure, the database can
rebuild itself from that log.
Database architecture
Database applications can be partitioned into one, two, or three parts or "tiers"
