Database Management Final
what is a wildcard operator in SQL statements?
*
In which of the following situations would one have to use an outer join in order to obtain the desired results?
A report is desired that lists all customers and the total of their orders during the most recent month, and includes customers who did not place an order during the month (their total will be zero).
Which of the following factors drive the need for data warehousing?
Businesses need an integrated view of company information
________ use the result of the outer query to determine the processing of the inner query.
Correlated subqueries
What counts ONLY rows that contain a value?
Count
A class of database technology used to store textual and other unstructured data is called:
NoSQL.
Advances in information systems that contributed to the emergence of data warehousing
a. Improvements in database technology, particularly the relational data model b. Advances in computer hardware, especially affordable mass storage and parallel computer architectures c. Advances in middleware products that enabled enterprise database connectivity across heterogeneous platforms
The MERGE command:
allows one to combine the INSERT and UPDATE operations.
A join in which the joining condition is based on equality between values in the common columns is called a(n):
both equi-join and natural join.
A join operation:
causes two tables with a common domain to be combined into a single table or view
When we consider data in the data warehouse to be time-variant, we mean:
data in the warehouse contain a time dimension so that they may be used to study trends and changes
A logical data mart is a(n):
data mart created by a relational view of a slightly denormalized data warehouse.
A star schema contains both fact and ________ tables.
dimension
A database action that results from a transaction is called a(n):
event.
The outer join syntax does not apply easily to a join condition of more than ________ tables.
four
Embedded SQL consists of:
hard-coded SQL statements included in a program written in another language.
One major advantage of the outer join is that:
information is not lost
The analysis of summarized data to support decision making is called
informational processing.
A dependent data mart
is filled exclusively from the enterprise data warehouse with reconciled data.
The most commonly used form of join operation is the:
natural join
A join that is based upon equality between values in two common columns with the same name and where one duplicate column has been removed is called a(n):
natural join.
The use of a set of graphical tools that provides users with multidimensional views of their data is called:
on-line analytical processing (OLAP).
A join in which rows that do not have matching values in common columns are still included in the result table is called a(n):
outer join
One characteristic of independent data marts is complexity for end users when they need to access data in separate data marts. This complexity is caused by not only having to access data from separate databases, but also from:
the possibility of a new generation of inconsistent data systems, the data marts themselves.
A named set of SQL statements that are considered when a data modification occurs are called:
triggers