MIS 380 FINAL
Denormalization _____.
- requires a modification of the logical database design result - introduces data redundancy - can improve database performance - avoids joins
What causes the basic incompatibility between current third generation programming languages and database processing with SQL?
3GLs process a single record while SQL processes a set of records.
What is the comparison operator for the Between operator?
>=and<=
What service does ADO provide?
A comprehensive front end to OLE DB
Which of the following is true regarding adding indexes to a relational database?
Adding too many indexes can slow overall performance if the data is highly volatile
An ODBC driver provides what service for an IS application?
Allows different languages to connect to various DBMSs
What is the advantage of using an XSD file over a DTD file?
An XSD file is itself an XML file
The most common data indexing in use today is the
B+ tree index
Which of the following aggregate functions CANNOT work on computed fields? Sum, Count, Avg, min, max
COUNT
What are aggregate functions?
Count, Avg, Max, Min, Sum
The keyword 'distinct' is used to do what?
Eliminate duplicate rows
What does the _symbol mean when using the LIKE operator and comparing a pattern or substring?
Exactly one character is skipped
What does the acronym XML stand for?
Extensible Markup Language
The two clauses that can be used to describe JOIN conditions are the ___clause & the ____clause
FROM clause & WHERE clause
What services does OLE DB provide?
Interfaces to both relational and non-relational databases
What does ODBC stand for?
Open database connectivity
What is the primary purpose of a data cube?
Provide aggregate data along specific dimensions
Data synchronization is required for what types of distributed databases?
Replicated databases
What are the three most common SQL clauses
SELECT, FROM, WHERE
Aggregate functions can appear in which clauses of an SQL query?
SELECT, HAVING
Security attacks on a database to access unauthorized data by spoofing the SQL statements is referred to as _______.
SQL Injection Attacks
A JOIN statement will always contain?
Two tables and a join on condition
Which of the following lists gives the order of execution of an SQL Statement by the DBMS? a. FROM, WHERE, SELECT b. FROM, SELECT, WHERE c. WHERE FROM SELECT d. SELECT FROM WHERE
a. FROM, WHERE, SELECT
Which of the following lists are change queries -- that change in the database? a. insert, update, delete b. add, change, delete c. insert, change, delete d. add, update, remove
a. insert, update, delete
Adding subset tables _____. a. None of the above b. avoids joins c. is one of the first physical design techniques that dshould be used to improve performance d. All of the above e. requires clustering files
a. none of the above
When performing OLAP processing on data in a data warehouse, the technique that is best for finding connections between attributes, where one attribute is often found paired with another attribute is called what?
association analysis
The main purpose of the "substituting foreign keys" physical design technique is to _____.
avoid joins
For any given application there are three basic services that must be provided. Which of the following is NOT one of the three? a. A data access function b. A network connection function c. A business function d. A display function
b. A network connection function
Which of the following lists includes items that can be included in the FROM clause? (check all that apply) a. Conditional statements, subqueries b. Table Names, literal constants c. Subqueries, Table names d. Table names, View names
c & d
Aggregate functions operate on what? a. Values on a single row b. Values across mult rows & columns c. Values across mult rows d. Values across mult columns
c. Values across multiple rows
In a conditional statement in the WHERE clause, which of the following statements is the correct way to test for 'boots' and heels' ?
category = 'boots' OR category = 'heels'
One purpose of defining a new, single field primary key to replace an existing multi-field primary key is _____. a.the multi-field key is clumsy to use as a foreign key in other tables b. None of the above c. the multi-field key cannot be indexed d. to avoid joins e. All of the above.
d. all of the above
which of the following lists gives the correct order of clauses in a well-formed SQL statement? a. Select, from, having, group by, where, order by b. Select, from, having, where, group by, order by c. select, from, where, order by, group by, having d. select, from, where, group by, having , order by
d. select, from, where, group by, having , order by
One way to distribute data to multiple locations is to make copies of the database at each location. What is this method called?
data replication
A star schema consists of what kinds of information?
fact tables and dimension tables
Rotational delay refers to the time it takes ____
for the data to arrive under the read/write head after the read/write head is switched on
Which of the following is NOT a function of an ODBC driver?
interpret SQL statements
In database technology what is the most important aspect of a transaction?
it is all or nothing processing
If an index involves a non-unique field of a file
it may return multiple records when it is used to access the file
The reason for performing physical database design is because the tables resulting from the logical database design _____.
may not perform well enough
Of the following, the one that is the least likely candidate to have an index built over it is a(n) _____.
non-search attribute
In a magnetic disk device, a cylinder consists of ___
one track from each recording surface, one above the other
The clustering files technique improves relational database performance by _____.
placing related rows of different tables near each other on the disk
An index built over a single field of a file ___
provides direct access to the file
Hashed files _____.
require synonym pointer chains when collisions occur
In the division remainder hashing algorithm _____.
the remainder points to the record location in the file
Of the following factors, the one least likely to affect database performance is ____
the speed of transferring data from the CPU to primary memory
A three-tier application that limits the functionality on the client layer to data entry and data display is sometimes called a(n) ________ _______ configuration.
thin client
The measure of the number of queries from simultaneous users that must be satisfied in a given period of time by the application set and the database that supports it is called _____.
throughput
All of the following are inputs into the physical database design process, except _____.
unnormalized data
Splitting off large text attributes into a separate table is a form of _____
vertical partitioning
When must an alias name be included within quote marks?
when it contains a space
Which of the following aggregate functions only work on numeric columns? SUM, COUNT, MAX, MIN, AVG
SUM & AVG
The data in a data mart is most frequently organized in what type of schema?
Star schema
What does SQL stand for?
Structured Query Language
In a vertically partitioned distributed database how is the data distributed across locations?
Tables have columns that are unique to each location
In a horizontally partitioned distributed database how is the data distributed across locations?
Tables have rows that are unique to each location
What is meant when a text field contains a null value?
The field has an undetermined data value
By adding the GROUP by clause to the query what happens to the rows?
The query is changed from rows to groups