precourse assessment

In the relational model, _____ are important because they are used to ensure that each row in a table is uniquely identifiable. keys indexes relations logical structures

keys

Automatic query optimization means that the: DBMS finds the most cost-effective access path without user intervention. optimization takes place at compilation time by the programmer. database access strategy is defined when the program is executed. optimization process is scheduled and selected by the end user or programmer.

DBMS finds the most cost-effective access path without user intervention

_____ can render data useless to unauthorized users who might have violated some of the database security layers. Password security Physical security Data encryption Access rights

Data encryption

Which statement describes a feature of Oracle sequences? Dropping a sequence does not delete values assigned to table attributes; it deletes only the sequence object from the database. An Oracle sequence uses the identity column property to automatically number rows. Oracle sequences are tied to columns and tables. Oracle sequences generate a character string that can be assigned to tables.

Dropping a sequence does not delete value assigned to table attributes; it deletes only the sequence object from the database

An operational database is sometimes referred to as an enterprise database. True False

False

Flume is a tool for converting data back and forth between a relational database and the HDFS. True False

False

In the single-site processing, single-site data (SPSD) scenario, all processing must be done on the end user's side of the system. True False

False

MySQL allows multiple triggering conditions per trigger. True False

False

The effects of bad database design, implementation, and management are magnified in an environment in which the number of transactions is less than one hundred. True False

False

Which of the following is true of a web application server? It is Microsoft's implementation of a superset of the SQL Access Group CLI standard for database access. It provides security and authentication of users through user IDs and passwords. It runs on the client machine, freeing server resources. It is automatically invoked by the browser when needed.

It provides security and authentication of users through user IDs and passwords

_____ transparency exists when the end user or programmer must specify the database fragment names but does not need to specify where these fragments are located. Transaction Location Fragmentation Local mapping

Location

______ minimizes the number of disk reads necessary to retrieve a row of data. Column-oriented database Row-centric storage Column-family database Column-centric storage

Row-centric storage

Which query is used to list a unique value for V_CODE, where the list will produce only a list of those values that are different from one another? SELECT ONLY V_CODE FROM PRODUCT; SELECT DIFFERENT V_CODE FROM PRODUCT; SELECT UNIQUE V_CODE FROM PRODUCT; SELECT DISTINCT V_CODE FROM PRODUCT;

SELECT DISTINCT V_CODE FROM PRODUCT;

Which of the following is a specialization hierarchy overlapping constraint scenario in case of partial completeness? Supertype has optional subtypes. Subtype does not have a supertype. Subtype discriminators cannot be null. Subtype sets are unique.

Supertyep has optional subtypes

Fully equivalent means that the optimized query results are always the same as the original query. True False

True

The database contents might be loaded interactively or in batch mode using a variety of methods and devices including customized user programs. True False

True

The scheduler establishes the order in which the operations within concurrent transactions are executed. True False

True

The storage locations for multiple backups must include sites inside and outside the organization. True or False

True

An atomic attribute _____. cannot be further subdivided displays multiplicity is always chosen to be a foreign key cannot exist in a relational table

cannot be further subdivided

A(n) _____ specifically reserves access to the transaction that locked the object. shared lock deadlock binary lock exclusive lock

exclusive lock

The reliance on _____ as the design methodology for relational databases is seen as a stumbling block to its use in OLAP systems. normalization multidimensional schema denormalization star schema

normalization

The _____ component of a CASE tool produces the information system's input/output formats. analysis program document generator screen painter and report generator graphics

screen painter and report generator

Which of the following is true of business rules? They provide a framework for the company's self-actualization. They allow the designer to set company policies with regard to data. They can serve as a communication tool between the users and designers. They allow the designer to develop business processes.

they can serve as a communication tool between the users and designers

Advanced OLAP feature become more useful when access to them is kept simple. True False

true

A _____ entity has a primary key that is partially or totally derived from the parent entity in the relationship. weak child business strong

weak