The ___________ R S keeps tuple in the first {left} relation R; if no matching tuple found in S, then the attribute of S in the join are filled with NULL values
o LEFT OUTER JOIN
o RIGHT OUTER JOIN
o FULL OUTER JOIN
o LEFT INNER JOIN
If a relation schema has more than one key, each is called a _______ key.
o Candidate
o Primary
o Public
o Foreign
A _________conflict arises when an attribute may have different domains in two schemas, e.g. pounds vs kilograms
o Domain
o Type
o Norming
o Constraints
UML _________ diagrams describe the dynamic relationships among components
o Behavioral
o Structural
o Class
o Direct
Objects in an object-oriented programming language exist only during program execution, therefore they are called transient objects; an object-oriented database can extend the existence of objects so that they are stored permanently, therefore they are called
o persistent object
o instance variable
o attribute
o object structure
_____ is the term used to refer to the problems that occur because of difference between the database model and the programming language model.
o Independence mismatch
o Denormalisation
o Redundancy
o Duplication
A __________________ is typically used to loop over the tuples in a query result
o Cursor {iterator variable}
o Shared variable
o Communication variables
o fetch
NULL values may mean value unknown, value exists but isn't available, and attribute does not apply to this tuple (value undefined)
A THETA JOIN uses any of the comparison operators =,<,> or (not equal)
For structured data, the schema information is mixed in with the data values, so it is sometimes referred to as self-describing data
The main advantage of using a function call interface is that it makes it easier to access multiple databases within the same application program
In PHP, Interpolating variables may occur within double-quoted or single-quoted strings
In PHP, the $d->query function takes an SQL command as its string argument and sends it to the database server for execution.
The ________________ property ensures that either all the database operations in a transaction are executed or none are
o Atomicity
o Transaction
o Isolation
o Concurrency
_______occurs when the same data is stored multiple times
o Normalisation
o Denormalization
o Persistent
Creating a database design that only stores each logical data item in only one place is the database is called______
o Normalization
The ________________ property allows several users to update the same data in a controlled manner so that result of the updates is correct
An entity cannot exist in a database merely by being a member of a subclass, it must also be a member of the superclass
An entity that is a member of a subclass may inherit one, some, or all the attributes of the entity as a member of the superclass.
The theoretical basis of the relational data model is set theory and first-order predicate logic
Semantic integrity constraints may be enforced using mechanisms called triggers and assertions.
When mapping a binary M:N relationship type R, create a new relation S to represent R, including as foreign key attributes in S the primary keys of the relations that are the participating entity types (their combination in S is the composite primary key of S).
$_SESSION − An associative array containing session variables available to the current script
PHP makes use of mail() function to send an email. This function requires three mandatory arguments that specify the recipient's email address, the subject of the the message and the actual message additionally there are other two optional parameters
The interpreter identifies variable names within double-quoted strings by their initial character $ and replaces them with the value in the variable. This is known as interpolating variables within strings. Interpolation does not occur in single-quoted strings
SQLJ was developed after JDBC, which is used for accessing SQL data- bases from Java using function calls
Most NoSQL databases support automatic __________, meaning that you get high availability and disaster recovery
processing
scalability
replication
All of the mentioned
The Web Services Architecture supports interaction between a service provider, service requestor, and service registry
Multi-line PHP comments start with // and end with #.
Define types of abstractions by the relations as "A is made of/composed of B,C,D"
Classification
Aggregation
Generalization
Specialization
FETCH commands are issued in the program; each FETCH moves the cursor to the next row in the result of the query, making it the cur- rent row and copying its attribute values into the C (host language) program variables specified in the FETCH command by an INTO clause.</text>
Define types of abstractions by the relations as "B,C,D are special cases of A"
A JDBC driver is basically an implementation of the function calls specified in the JDBC application programming interface (API) for a particular vendor's RDBMS
In PHP, a numeric array associates a numeric index with each element in the array.
Before being able to process JDBC function calls with Java, it is necessary to import the JDBC class libraries, which are called java.sql.*.
How can you change "Hansen" into "Nilsen" in the "LastName" column in the Persons table?
UPDATE Persons SET LastName='Hansen' WHERE LastName='Nilsen'
UPDATE Persons SET LastName='Nilsen' WHERE LastName='Hansen'
MODIFY Persons SET LastName='Hansen' WHERE LastName='Nilsen'
UPDATE FROM Persons SET LastName='Nilsen' WHERE LastName='Hansen'
Publisher table contains id and name columns. Id is auto incremented and name is of varchar(40) type. Which of the following queries will execute NOT correctly?
INSERT INTO Publisher (name) values ('O'Reilly');
INSERT INTO Publisher (name) values ('O Reilly');
INSERT INTO Publisher (name) values ('OReilly');
INSERT INTO Publisher (name) values ('O-Reilly');
What is the correct order of clauses for a proper SQL query?
SELECT, FROM, WHERE, GROUP BY, HAVING, ORDER BY
SELECT, FROM, WHERE, GROUP BY, ORDER BY, HAVING
SELECT, FROM, GROUP BY, WHERE, HAVING, ORDER BY
SELECT, FROM, WHERE, HAVING, GROUP BY, ORDER BY
SELECT, FROM, ORDER BY, WHERE, GROUP BY, HAVING
Which clause indicates the table(s) from which data is to be retrieved?
FROM
SELECT
WHERE
GROUP BY
HAVING
Which clause is executed first in a SQL query?
• WHERE
• SELECT
• ON
• TOP
• FROM
Which of the following DROP statements is INCORRECT?
• DROP TABLE
• DROP DATABASE
• DROP ROW
• DROP INDEX
Which of the following is NOT a language element of SQL?
Expression
Data mining
Query
Statement
Clause
Which operator is used to search for a specified pattern in a column?
LIKE
ALIASE
PATTERN
Which operator is used to select values within a range?
RANGE
AND
BETWEEN
OR
Which term is used to describe data organized in rows and columns?
Program
Index
Table
With SQL, how can you delete the records where the "Address" is "Almaty" in the Student Table?
DROP ROW Student ='Almaty' FROM Address
DELETE FROM Student ROW Address ='Almaty'
DROP ROW Address ='Almaty' FROM Student
DELETE ROW Address ='Almaty' FROM Student
With SQL, how can you return all the records from a table named "Persons" sorted descending by "FirstName"?
SELECT * FROM Persons GROUP BY FirstName DESC
SELECT * FROM Persons WHERE FirstName DESC
SELECT * FROM Persons ORDER BY FirstName
SELECT * FROM Persons ORDER BY FirstName DESC
With SQL, how can you return the number of records in the "Employee" table?
SELECT COUNT(*) FROM Employee
SELECT * FROM Employee GROUP BY
SELECT NUM(*) FROM Employee
RETURN COUNT(*) FROM Employee
With SQL, how do you select all the records from a table named "Persons" where the value of the column "FirstName" starts with an "a"?
SELECT * FROM Persons WHERE FirstName LIKE 'a%';
SELECT * FROM Persons WHERE FirstName LIKE '%a%';
SELECT All FROM Persons WHERE FirstName LIKE='a';
SELECT * FROM Persons WHERE FirstName LIKE 'a*';
With SQL, how do you select all the records from a table named "Persons" where the "FirstName" is "Alma" and the "LastName" is "Alimova"?
SELECT * FROM Persons WHERE FirstName=' Alma ' AND LastName=' Alimova'
SELECT * FROM Persons WHERE FirstName=' Alma ' OR LastName=' Alimova'
SELECT FROM Persons WHERE FirstName=' Alma ' AND LastName=' Alimova'
SELECT * FROM Persons HAVING FirstName=' Alma ' AND LastName=' Alimova'
Which of the following is not a NoSQL database ?
SQL Server
MongoDB
Cassandra
None of the mentioned
Which of the following is a NoSQL Database Type ?
SQL
Document databases
JSON
Which of the following is a wide-column store ?
Riak
Redis
An ODMS provides a unique identity to each independent object stored in the database via a unique, system-generated ________
object identifier (OID)
literals
indirect pointer
constructor
Define types of abstractions by the relations as "A is a member of class B
Define types of abstractions by the relations as "B is-an A, C is-an A, D is-an A"
How will you close a MySql database using PHP?
mysql_destroy
mysql_exit
mysql_end
mysql_close
How will you concatenate two strings?
Using . operator
Using + operator
Using add() function
Using append() function
How will you connect a MySql database using PHP?
mysql_connection
mysql_query
mysql_fetch_array
mysql_connect
How will you destroy a session in PHP?
session_destroy()
destroy_session()
$_SESSION['destroy']
$_SESSION['']
How will you start a session in PHP?
session_start()
start_session()
$_SESSION['start']
How will you unset a single session variable?
![CDATA[<?phpunset($_SESSION['counter']);?>]]
![CDATA[<?phpisset($_SESSION['counter']); ?>]]
$_SESSION['unset']
Identify factors to consider in choosing one DBMS over another. I. Organization-wide adoption of a certain philosophy (data model, vendor, methodology, tools). II. Familiarity of personnel with the system. III. Availability of vendor services.
I,II
I,II,III
II,III
I,III
In which type of PHP arrays the element values can be strings or integers?
numeric
associative
indexed
none
In XML schema, the tag ________________ is used to specify foreign keys
xsd:keyref
xsd:element
xsd: unique
xsd:foreignkey
NoSQL databases is used mainly for handling large volumes of ______________ data
unstructured
structured
semi-structured
all of the mentioned
Point out the wrong statement
Non Relational databases require that schemas be defined before you can add data
NoSQL databases are built to allow the insertion of data without a predefined schema
NewSQL databases are built to allow the insertion of data without a predefined schema
The ___ notation applies to user-defined subclasses of a specialization that must be ________, as illustrated by the specialization "every STUDENT must be either an GRADUATE_STUDENT, or a UNDERGRADUATE_STUDENT"
d, disjoint
j, joint
o, overlapping
u, union
The case of specialization what the same (real-world) entity may be a member of more than one subclass of the specialization for example, an alumnus may also be an employee and may also be a student pursuing an advanced degree (PERSON entity type, which is specialized into the subclasses {EMPLOYEE, ALUMNUS, STUDENT})
disjoint
joint
overlapping
union
This auto-global built-in array variable which provides the IP (Internet Protocol) address of the client user computer that is accessing the server, for example 129.107.61.8.
$_SERVER['SERVER_NAME']
$_SERVER['REMOTE_ADDRESS']
$_SERVER['REMOTE_HOST']
$_SERVER['PATH_INFO']
$_SERVER['QUERY_STRING']
This auto-global built-in array variable which provides the part of the URL address that comes after a backslash (/) at the end of the URL.
This auto-global built-in array variable which provides the string that holds parameters in a URL after a question mark (?) at the end of the URL. This can hold search parameters, for example
This auto-global built-in array variablewhich provides the Web site name of the server computer where the PHP interpreter is running.
What does PHP stands for
Personal Hypertext Processor
PHP: Hypertext Preprocessor
Private Home Page
Private Hypertext Preprocessor
What does S in BASE refers to?
System Consistence
System Availability
Changing System
System Stability
[What does the term "I" expands to in the term "ACID"?
Isolated
Inseparable
Indispensable
Insulted
What does XML stand for?
eXtensible Markup Language
Example Markup Language
X-Markup Language
eXtra Modern Link
What does XSL stand for?
eXtensible Stylesheet Language
eXtra Style Language
eXpandable Style Language
eXtensible Style Listing
What is the correct syntax of the declaration which defines the XML version?
<?xml version="1.0" />
<?xml version="1.0"?>
<xml version="1.0" />
Which company did Cassandra was primarily developed in?
Apache
Facebook
Google
Amazon
Which feature of CAP refers to load balancing
None of these
С
А
Р
Which of the following are the simplest NoSQL databases
Key-value
Wide-column
Document
Which of the following is correct about PHP
PHP is a recursive acronym for "PHP: Hypertext Preprocessor".]
PHP is a server side scripting language that is embedded in HTML
It is used to manage dynamic content, databases, session tracking, even build entire e-commerce sites
All of these statement
Which of the following is correct about variable naming rules?
Variable names must begin with a letter or underscore character.
A variable name can consist of numbers, letters, underscores.
you cannot use characters like + , - , % , ( , ) . & , etc in a variable name.
Which of the following is not a NoSQL database?
Which of the following method can be used to create a MySql database using PHP?
mysql_connect()
mysql_query()
mysql_close()
None of the above
Which of them could not be applied to techniques for looping through arrays in PHP
$courses = ('Database', 'OS', 'Graphics', 'Data Mining');
$courses = array('Database', 'OS', 'Graphics', 'Data Mining');
$teaching = array('Database' => 'Smith', 'OS' => 'Carrick', 'Graphics' => 'Kam');
$teaching['Graphics'] = 'Benson';
$alt_row_color = array('blue', 'yellow');
A key difference between structured and semistructured data concerns how the schema constructs (such as the names of attributes, relationships, and entity types) are handled.
A large database typically has large transaction volumes and rates, is used in service sector industries, and runs 24/7
A library of functions, also known as an application programming interface (API), is used to access the database
A safer way to do inserts and other queries is through the use of placeholders (specified by the ? symbol) in PHP
Associative array − An array with strings as index. This stores element values in association with key values rather than in a strict linear index order.
In SQLJ, an iterator is a type of object associated with a collection (set or multiset) of records in a query result.
In SQLJ, embedded SQL commands are preceded by #sql.
In XML schema, it is possible to specify constraints that correspond to unique and primary key constraints in a relational database, as well as foreign keys constraints.
Interfaces are defined to provide a common function names to the implementers. Different implementers can implement those interfaces according to their requirements. You can say, interfaces are skeletons which are implemented by developers.
Numeric array − An array with a numeric index. Values are stored and accessed in linear fashion.
OPEN CURSOR command is issued to indicate that we are done with processing the result of the query associated with that cursor.
PHP is written in C and usually comes installed with Unix; for other operating systems, the PHP interpreter can be downloaded from http://www.php.net.
The cursor is declared when the SQL query command is declared in the program. Later in the program, an OPEN CURSOR command fetches the query result from the database and sets the cursor to a position before the first row in the result of the query
The typical mechanisms for making an object persistent are naming and reachability
XML attribute values must always be enclosed in quotes
XML elements cannot be empty
XML's goal is to replace HTML
XQuery is the language for querying XML data
The case represents a single superclass/subclass relationship with more than one superclass, where the superclasses represent different entity types
When a database design is in ____________, each value in a tuple is in atomic value.
First normal form
Second normal form
Third normal form
Forth normal form
Redundancy leads to three potential problems. Briefly describe each of the three.
Duplication of effort
Storage space is wasted
Multiple occurrences of data may become inconsistent
What two things does minimizing redundancy imply
Minimizing redundant storage of the same information.
Reducing the need for multiple updates to maintain consistency across multiple copies of the same information.
What are the four informal guidelines that may be used to measure the quality of a relation schema design?
Making sure the semantics of the attributes is clear in the schema.
Reducing the redundant information in tuples.
Reducing the NULL values in tuples.
Disallowing the possibility of generating spurious tuples.
What are the three goals of database design?
Satisfy the information content requirements of the specified users and applications.
Provide a natural and easy-to-understand structuring of the information.
Support processing requirements and any performance objectives
Identify two of the three factors to consider in choosing one DBMS over another
Organization-wide adoption of a certain philosophy (data model, vendor, methodology, tools).
Familiarity of personnel with the system
Availability of vendor services
Identify the three criteria to guide the choice of physical database design options
Response time.
Space utilization
Transaction throughput.
A join operation joins _____ tables into _____.
three, two
three, one
four, two
two, one
A primary key should be defined as: I. NULL II. NOT NULL III. Optional
I, II
I, III
II only
I, II, III
A subquery in an SQL SELECT statement is enclosed in:
braces -- {...}.
CAPITAL LETTERS
parenthesis -- (...)
brackets -- [...].
SQL query and modification commands make up a(n) ________ .
DML
DDL
HTML
XML
The command to eliminate a table from a database is:
• REMOVE TABLE TableName
• DROP TABLE TableName
• DELETE TABLE TableName
• UPDATE TABLE TableName
________ stores are used to store information about networks, such as social connections.
• Key-value
• Wide-column
• Graph
A ___________ is an indirect functional dependency, one in which X->Z only by virtue of X->Y and Y->Z
• Multivalued Dependencies
• Join Dependency
• Trivial Functional Dependency
• Transitive Dependencies
A table is in 3NF if it is in 2NF and if it has no ____________
• Functional Dependencies
A table is in BCNF if it is in 3NF and if every determinant is a ___________ key.
• Dependent
• Normal
• Candidate
Both Normal and Candidate
Anomalies are avoided by splitting the offending relation into multiple relations, is also known as
• Accupressure
• Decomposition
• Both Decomposition and Precomposition
• Precomposition
Every time attribute A appears, it is matched with the same value of attribute B, but not the same value of attribute C. Therefore, it is true that:
A-->B
A-->C
A-->(B,C)
(B,C)-->A
For select operation the ________ appear in the subscript and the ___________ argument appears in the parenthesis after the sigma.
• Predicates, relation
• Relation, Predicates
• Operation, Predicates
• Relation, Operation
If X -> Y, which of the following would make Y fully dependent on X?
• X consists of multiple attributes
• Y is a single attribute
• Y consists of multiple attributes
• X is a single attribute
In a given relationship R, if an attribute A uniquely defines all other attributes, then the attribute A is a key attribute which is also known as the _________ key.
• Join
• Functional
• None of the Mentioned
In EER modeling, specialization is the process of generating
• entities out of attributes
• attributes out of entities
• subclasses out of superclasses
• superclasses out of subclasses
In precedence of set operators the expression is evaluated from
• Left to left
• Left to right
• Right to left
• From user specification
The ___________ operation, denoted by −, allows us to find tuples that are in one relation but are not in another.
• Union
• Set-difference
• Difference
• Intersection
The functional dependency X -> Y is true if
a value of X uniquely determines a value of Y
the value of Y depends on the collective values of X
the value of X depends on the collective values of Y
a value of Y uniquely determines a value of X
The result of a set difference operation r - s will be
those tuples that are in s but not in r
those tuples that are in r but not in s
tuples in s after deducting their values by the corresponding values in the tuples in r
tuples in r after deducting their values by the corresponding values in the tuples in s
What does a projection operation do?
It extends the number of rows in a table.
It extends the number of columns in a table
It selects columns from a table
It selects rows from a table.
When the values in one or more attributes being used as a foreign key must exist in another set of one or more attributes in another table, we have created a(n)
Transitive Dependency
Insertion Anomaly
Referential Integrity Constraint
Normal Form
Which is a join condition contains an equality operator
Equijoins
Cartesian
Natural
Left
Which is a unary operation
Selection operation
Primitive operation
Projection operation
Generalized selection
Which of the following is a fundamental operation in relational algebra
Set intersection
Natural join
Assignment
Which of the following is not a restriction for a table to be a relation?
The cells of the table must contain a single value
The columns must be ordered
No two rows in a table may be identical
Which of the following is used to denote the selection operation in relational algebra?
Pi
Sigma
Lambda
Omega
Y is transitively dependent on X, if
X -> A, B and Y -> A, B
X -> Y and A -> Y
X -> A, B and A -> Y
X -> Y and Y -> A
For two tables to be union compatible, corresponding columns from each table should have which of the following?
the same domain
the same name
different domains
different names
