Questão 1
Questão
Which of the following is a benefit of using a DBMS?
Responda
-
They provide full security to data using private/public key encryption
-
They create automatic backups
-
They help create an environment for end users to have access to more data
-
They provide seamless Internet access to database data
Questão 2
Questão
The hierarchical database model is based on a ____.
Responda
-
tree structure
-
lack of a parent segment
-
lack of a child segment
-
matrix
Questão 3
Questão
Because an RDBMS hides the system's complexity from the user/designer, ____.
Responda
-
it does not exhibit data independence
-
it does not exhibit structural independence
-
data management is easier
-
data management is very difficult
Questão 4
Questão
The ERD is used to graphically represent the ____ database model.
Responda
-
condensed
-
physical
-
logical
-
conceptual
Questão 5
Questão
The property of ____ enables an entity subtype to inherit the attributes and relationships of the supertype.
Responda
-
subtype discriminator
-
inheritance
-
specialization hierarchy
-
entity supertype
Questão 6
Questão
At the implementation level, the supertype and its subtype(s) depicted in the specialization hierarchy maintain a ____ relationship.
Questão 7
Questão
Which command would be used to delete the table row where the P_Code = '2238/QPD'?
Responda
-
DELETE FROM PRODUCT
WHERE P_CODE = '2238/QPD';
-
REMOVE FROM PRODUCT
WHERE P_CODE = '2238/QPD';
-
ERASE FROM PRODUCT
WHERE P_CODE = '2238/QPD';
-
ROLLBACK FROM PRODUCT
WHERE P_CODE = '2238/QPD';
Questão 8
Questão
Which command is used to select partial table contents?
Responda
-
SELECT <column(s)>
FROM <Table name>
WHERE <Item>;
-
LIST <column(s)>
FROM <Table name>
WHERE <Conditions>;
-
SELECT <column(s)>
FROM <Table name>
WHERE <Conditions>;
-
LIST<column(s)>
FROM <Table name>
WHERE <Item>;
Questão 9
Questão
Which query will output the table contents when the value of V_CODE is equal to 21344?
Responda
-
SELECT P_DESCRIPT, P_INDATE, P_PRICE, V_CODE
FROM PRODUCT
WHERE V_CODE <> 21344;
-
SELECT P_DESCRIPT, P_INDATE, P_PRICE, V_CODE
FROM PRODUCT
WHERE V_CODE <= 21344;
-
SELECT P_DESCRIPT, P_INDATE, P_PRICE, V_CODE
FROM PRODUCT
WHERE V_CODE = 21344;
-
SELECT P_DESCRIPT, P_INDATE, P_PRICE, V_CODE
FROM PRODUCT
WHERE V_CODE => 21344;
Questão 10
Questão
What is the command used to list the P_CODE, P_DESCRIPT, P_INDATE, and P_PRICE fields from the Product table in ascending order by P_PRICE?
Responda
-
SELECT P_CODE, P_DESCRIPT, P_INDATE, P_PRICE
FROM PRODUCT
SEQUENCE BY P_PRICE;
-
SELECT P_CODE, P_DESCRIPT, P_INDATE, P_PRICE
FROM PRODUCT
LIST BY P_PRICE;
-
SELECT P_CODE, P_DESCRIPT, P_INDATE, P_PRICE
FROM PRODUCT
ORDER BY P_PRICE;
-
SELECT P_CODE, P_DESCRIPT, P_INDATE, P_PRICE
FROM PRODUCT
ASCENDING BY P_PRICE;
Questão 11
Questão
The basic SQL aggregate function that gives the total of all values for a selected attribute in a given column is ____.
Questão 12
Questão
____ is used to tally the number of specific "values" of an attribute.
Questão 13
Questão
UPDATE tablename
*****
[WHERE conditionlist];
What command replaces the ***** in the above statement?
Questão 14
Questão
When using a(n) ____ join, only rows that meet the given criteria are returned.
Questão 15
Questão
What is the syntax for a left outer join?
Responda
-
SELECT column-list
FROM table1 OUTER JOIN table2 LEFT
WHERE join-condition
-
SELECT column-list
FROM table1 LEFT [OUTER] JOIN table2
ON join-condition
-
SELECT column-list
WHERE LEFT table1 = table 2
-
SELECT column-list
FROM table1 LEFT table2 [JOIN]
WHERE join-condition
Questão 16
Questão
In subquery terminology, the first query in the SQL statement is known as the ____ query.
Questão 17
Questão
In a subquery, which query is executed first?
Responda
-
leftmost
-
rightmost
-
innermost
-
outermost
Questão 18
Questão
Creating the conceptual design, selecting DBMS software, creating the logical design, and creating the physical design are part of the ____ phase.
Questão 19
Questão
Which of the conceptual design steps defines entities, attributes, and relationships?
Responda
-
Database analysis and requirements
-
Entity relationship modeling and normalization
-
Data model verification
-
Distributed database design
Questão 20
Questão
What is the primary objective of database design?
Responda
-
To create the most efficient database possible
-
To create complete, normalized, nonredundant, and fully integrated conceptual, logical, and physical database models
-
To create the fastest queries
-
To be able to add data quickly
Questão 21
Questão
The most common algorithms for concurrency control are locks, ____ stamping, and optimistic methods.
Questão 22
Questão
____ requires that all operations of a transaction be completed.
Responda
-
Specificity
-
Atomicity
-
Durability
-
Time Stamping
Questão 23
Questão
The ____ establishes the order in which the operations within concurrent transactions are executed.
Responda
-
transaction log
-
timer
-
lock manager
-
scheduler
Questão 24
Questão
When is the implicit beginning of a transaction?
Responda
-
When the database is started
-
When a table is accessed for the first time
-
When the first SQL statement is encountered
-
When the COMMIT command is issued
Questão 25
Questão
A(n) ____ phase in a two-phase lock is when a transaction releases all locks and cannot obtain any new lock.
Responda
-
growing
-
shrinking
-
locking
-
unlocking
Questão 26
Questão
What is a consistent database?
Responda
-
One in which all tables have foreign keys
-
One in which all data integrity constraints are satisfied
-
One in which all tables are normalized
-
One in which all SQL statements only update one table at a time
Questão 27
Questão
A transaction acquires a ____ prior to data access.
Questão 28
Questão
Changes are permanently applied to the database during the ____ phase of a transaction.
Responda
-
commit
-
write
-
input
-
output
Questão 29
Questão
The phenomenon of ____ occurs when two transactions, T1 and T2, are executed concurrently and the first transaction (T1) is rolled back after the second transaction (T2) has already accessed the uncommitted data—thus violating the isolation property of transactions.
Responda
-
lost updates
-
uncommitted data
-
transaction failure
-
inconsistent retrieval
Questão 30
Questão
____ occur when a transaction calculates some summary (aggregate) functions over a set of data while other transactions are updating the data.
Responda
-
lost updates
-
uncommitted data
-
transaction failures
-
inconsistent retrievals
Questão 31
Questão
The scheduler facilitates data ____ to ensure that two transactions do not update the same data element at the same time.
Responda
-
durability
-
isolation
-
atomicity
-
serializability
Questão 32
Questão
Which is not a DML statement?
Responda
-
CREATE TABLE
-
SELECT
-
INSERT
-
DELETE
Questão 33
Questão
What feature is a DDBMS disadvantage?
Questão 34
Questão
What feature is a DDBMS advantage?
Responda
-
Greater difficulty in managing the data environment
-
Less danger of a single-point failure
-
Increased training cost
-
Complexity of management and control
Questão 35
Questão
____ distributed database systems integrate different types of centralized DBMSs over a network.
Responda
-
Homogeneous
-
Heterogeneous
-
Fully homogeneous
-
Fully heterogeneous
Questão 36
Questão
____ transparency allows a transaction to update data at several network sites.
Responda
-
Transaction
-
Distribution
-
Failure
-
Performance
Questão 37
Questão
____ transparency ensures that the system will continue to operate in the event of a node failure.
Responda
-
Transaction
-
Distribution
-
Failure
-
Performance
Questão 38
Questão
The ____ contains the description of the entire database as seen by the database administrator.
Responda
-
distributed global dictionary
-
distributed data dictionary
-
distributed global schema
-
distributed data schema
Questão 39
Questão
____ query optimization means that the DDBMS finds the most cost-effective access path without user intervention.
Responda
-
Static
-
Dynamic
-
Automatic
-
Commit
Questão 40
Questão
____ query optimization takes place at execution time.
Responda
-
Automatic
-
Static
-
Manual
-
Dynamic