finalexam studyset

Query Processing involves which of the following steps:

- Scanning query tokens - Parsing to check query syntax - Validation check of all attribute and relation names - Creation of a query graph - Devise a Query execution strategy

For non-disjoint and/or non-complete class hierarchy, which of the following statements are true when mapping from ER to relational model.

-a table is created for each super class entity set according to normal entity set translation method. - a table is created for each subclass entity set with a column for each of the attributes of that entity set plus one for each attributes of the primary key of the super class entity set

On the XML below, which XPath expression will return all of the values of title attributes? <slideshow title="Sample Slide Show" date="Date of publication" author="Yours Truly" > <!-- TITLE SLIDE --> <slide type="all"> <title>Wake up to WonderWidgets!</title> </slide> <!-- OVERVIEW --> <slide type="all"> <title>Overview</title> <item>Why <em>WonderWidgets</em> are great</item> <item>Who <em>buys</em> WonderWidgets</item> </slide> </slideshow>

//@title

Assume that a relation R has the following properties. What is the normal form of R? Has no multi-valued attributes Has no partial key dependencies Has attributes with atomic domains Has transitive dependencies

1NF & 2NF

The database system must take special actions to ensure that transactions operate properly without interference from concurrently executing database statements. This property is referred to as _________.

Isolation

Which of the following provides the application-to-JDBC Manager connection.

JDBC API

Which statement about JDBC is true?

JDBC stands for Java Database Connectivity

During translation of SQL queries into relational algebra queries, Anti-join is used for unnesting ________ subqueries.

NOT EXISTS, NOT IN, ALL

The type of XML Parsing that is parses an XML document based on expression and is used extensively in conjunction with XSLT.

XPath Parsing

Which one of the following is always a single-valued attribute?

a person's age

During mapping weak entity sets of (E)ER model to relational model, primary key of the weak entity set is

discriminator plus foreign key

For disjoint AND complete mapping class hierarchy, a table is created for the super class entity set during mapping to relational model.

false

For many-to-many relationships being represented in relational model, primary key of the new schema is the foreign key of relation with less cardinality

false

Considering functional dependency, one in which removal from some attributes must affect dependency is called ________.

full functional dependency

All functional dependencies must _________.

have attributes of the same table

Well formed XML document means

must contain one or more elements and root element must contain all other elements

Represents a pre-compiled and/or parameterized query

PreparedStatement

The goals for mapping a (E)ER model to Relational model are:

Preserve all information Minimize null values Maintain constraints to extent possible

Corresponds to a cursor in the database server

ResultSet

SQL query: Retrieve the names of all the Person's who have at least a post with no likes and no comments

SELECT Distinct PE.FullName FROM Post PO, Person PE WHERE PO.PersonNick = PE NickName AND PO.PostID NOT IN (SELECT PostID FROM Likes) AND PostID NOT IN (SELECT PostID FROM Comment)

Represents a query to the database

Statement

Which of the following are not benefits of XML over traditional relational data modelling?

Support for Large Objects (LOBs)

For mapping one to one relationship without total participation from ER model to relational model, the following is true.

There is one column for each participating entity set's primary key.

In JDBC, it is a good practice to use standard SQL statement and avoid using db specific query until necessary.

True

Which type of driver provides JDBC access via one or more ODBC drivers?

Type 1

How do you update a SQL table?

UPDATE ______ SET _________ WHERE ________

Which of the following has "all-or-none" property in Transaction processing?

Atomicity

A transaction is delimited by statements (or function calls) of the form __________.

Begin transaction and End transaction

Represents the socket between client and server

Connection

_________ states that only valid data will be written to the database.

Consistency

Assume that a relation R has the following properties. What is the normal form of R? No multi-valued attributes No partial key dependencies

Second Normal Form

When XML is used as a DDL, we want to ensure the XML conforms to this so structural constraints may be specified:

DTD or XML Schema

During translation of SQL queries into relational algebra queries, Semi-join is used for unnesting ________ subqueries.

EXISTS, IN, ANY

In the __________ normal form, a composite attribute is converted to individual attributes.

First

Which is a bottom-up approach to database design that decomposes unsatisfactory relations by breaking up their attributes into smaller relations?

Normalization

Composite attribute in ER model is represented in relational model as ________________.

One column for each component attribute and NO column for the composite attribute