sdp 6

Question 1 of 113

1

The PEAR DB functions can be accessed using DB::<function_name>.

Select one of the following:

True
False

Explanation

Question 2 of 113

1

The string argument of the function for connecting to a database is of the format <DBMS software>://<user account>:<password>@<database server>

Select one of the following:

True
False

Explanation

Question 3 of 113

1

The PEAR DB functon for connecting to a database is called DB::linkto database('string').

Select one of the following:

True
False

Explanation

Question 4 of 113

1

• The DBMS software in <DBMS software>://<user account>:<password>@<database server> stands for the particular DBMS software package being connected to: for example mysqli for versions of MySQL starting with version 4.1.2

Select one of the following:

True
False

Explanation

Question 5 of 113

1

• The PEAR DB function DB::is Error can be used to determine whether any database access operation was successful or not.

Select one of the following:

True
False

Explanation

Question 6 of 113

1

• In PHP, an _____ array provides pairs of key=>value elements; the value of an element is referenced through its key and all key values in a particular array must be unique.

Select one of the following:

Numeric
Value
String
Associative

Explanation

Question 7 of 113

1

• Multi-line PHP comments start with // and end with #.

Select one of the following:

True
False

Explanation

Question 8 of 113

1

• PHP written in C and usually comes installed with Unix: for other operating systems, the PHP interpreter can be downloaded from http://www.php.net

Select one of the following:

True
False

Explanation

Question 9 of 113

1

• The PHP start tag is <?php and end the tag is ?>.

Select one of the following:

True
False

Explanation

Question 10 of 113

1

• Web pages, where part of the information is extracted from databases or other data source, are called dynamic Web pages

Select one of the following:

True
False

Explanation

Question 11 of 113

1

• In PHP, a ____ array associates a numeric index with each element in the array

Select one of the following:

Numeric
Associated
Variable
String

Explanation

Question 12 of 113

1

• PHP variable names start with a $ sign and can include characters, numbers, and the underscore character

Select one of the following:

True
False

Explanation

Question 13 of 113

1

• Interpolating variables occurs only within single-quoted strings.

Select one of the following:

True
False

Explanation

Question 14 of 113

1

• PHP programs are executed on the client.

Select one of the following:

True
False

Explanation

Question 15 of 113

1

• The auto-global predefined PHP variable $_POST is an array that holds all the values entered through form parameters.

Select one of the following:

True
False

Explanation

Question 16 of 113

1

• JDBC does not distinguish between queries that return single tuples and those that return multiple tuples.

Select one of the following:

True
False

Explanation

Question 17 of 113

1

• The JDBC _____ libraries are called java.sql.*

Select one of the following:

Method
Function
Class

Explanation

Question 18 of 113

1

• What are the advantages and disadvantages of the embedded SQL approach.

Select one or more of the following:

The main advantage is the query text is part of the source code can be checked for syntax errors and validated against the database schema at compile time. The program is quite readable. Since queries are known in advance, the choice of program variables to hold query results is simple.
The main advantage is flexibility in generating queries at runtime. Also, the library of function calls approach is able to call multiple data program.
The main disadvantage is the query text is part of the source code can be checked for syntax errors and validated against the database schema at compile time. The program is quite readable. Since queries are known in advance, the choice of program variables to hold query results is simple.
Disadvantage are more complex programming, inability to do checking at compile time, and concerns about SQL runtime errors.
Disadvantage are the loss of flexibility in changing the query the query at runtime and that all changes to queries must be recompiled.

Explanation

Question 19 of 113

1

• The use of function calls is a more dynamic approach for database programming than embedded SQL.

Select one of the following:

True
False

Explanation

Question 20 of 113

1

• A _____ object is similar to a cursor in embedded SQL and an iterator in SQLJ.

Select one of the following:

Procedure
Function call
Result Set

Explanation

Question 21 of 113

1

• _____ is the part of the SQL standard that specifies how to write persistent stored modules.

Select one of the following:

SQL/PSM
XML
SQLJ
ResultSet

Explanation

Question 22 of 113

1

• Database stored procedures (aka persistent stored modules) are stored and executed by the DBMS at the database server.

Select one of the following:

True
False

Explanation

Question 23 of 113

1

• Discuss advantages and diadvantages to the library of function calls approach

Select one or more of the following:

Disadvantage are the loss of flexibility in changing the query at runtime and that all changes to queries must be recompiled.
The main advantage is flexibility in generating queries at runtime. Also, the library of function calls approach is able to call multiple data program.
The main advantage is flexibility in generating queries at compile time. Also, the library of function calls approach is able to call multiple single program.
Disadvantages are more complex programming, inability to do checking at compile time, and concerns about SQL runtime errors.
The main advantage is the query text is part of source code and can be checked for syntax errors and validated against the data. The program is quite readable.

Explanation

Question 24 of 113

1

• It is necessary to have a binding between the data types of the programming language and the attribute data types in the data model

Select one of the following:

True
False

Explanation

Question 25 of 113

1

• In SQLJ, embedded SQL commands are preceded by #sql.

Select one of the following:

True
False

Explanation

Question 26 of 113

1

• One advantage of using an SQLJ translator is that it is not necessary to install drivers such as a JDBC driver.

Select one of the following:

True
False

Explanation

Question 27 of 113

1

• Describe the three main approaches for database programming.

Select one or more of the following:

• Using a library of database functions. This approach provides what is known as an application programming interface (API) for accessing a database from applications programs.
• Using a library of database methods. This approach provides what is known as an application programming interface (API) for accessing a database from applications programs
• Embedded SQL. Embeding database commands in a general-purpose programming language. A preprocessor extracts the embedded SQL from the source code and replaces it with function calls to DBMS-generated code.
• Embedded SQL. Embeding database commands in a specific-purpose programming language. A preprocessor can not extract code, but function calls to be extracted to DBMS-generated code.
• Designing a new database programming language.
• Embedded SQL. Embeding database commands in a specific-purpose programming language. A preprocessor extracts the embedded SQL from the source code and replaces it with function calls to DBMS-generating code

Explanation

Question 28 of 113

1

• In XML _____ defines the set of commands (names) that can be used

Select one of the following:

• Namespace
• Valid
• Document
• Invalid

Explanation

Question 29 of 113

1

• In XML schema, the tag _____ is used tospecify primary keys.

Select one of the following:

• xs:element
• xsd:key
• psd:schema
• xs:sequence

Explanation

Question 30 of 113

1

• A * following an element name means the element can be repeated zero or one times (an optional, single-valued, nonrepeating elements)

Select one of the following:

True
False

Explanation

Question 31 of 113

1

• If an XML document is well-formed and follows a particular schema, it is _____

Select one of the following:

• Namespace
• Keys
• Invalid
• Valid

Explanation

Question 32 of 113

1

• The XML schema, it is possible to specify constraints that correspond to unique and primary key constraints ina relational database, as well as foreign keys constraints

Select one of the following:

True
False

Explanation

Question 33 of 113

1

• An element that does not have *, +, or ? following the element name means the element must appear exactly once in the document (a required, single-valued, nonrepeating element).

Select one of the following:

True
False

Explanation

Question 34 of 113

1

• A ? following an element name means that element can be repeated zero or more times in the document (an optional, mult-valued, repeating element).

Select one of the following:

True
False

Explanation

Question 35 of 113

1

• The basic object in XML is the XML document, which is structured using types and iterators.

Select one of the following:

True
False

Explanation

Question 36 of 113

1

• How does a well-formed XML document look like?

Select one or more of the following:

• It is syntactically correct: a non-single root element with every element including a matching pair of start/end tags within the start-end of the parent element
• It must finish with an XML declaration to indicate the version of XML.
• It is syntactically correct: a single root element with every element including a matching pair of start/end tags within the start-end tags of the parent element
• It is syntactically correct: a single root element with every element except a matching pair of start/end tags within the start-end tags of the parent elements
• It must start with an XML declaration to indicate the version of XML

Explanation

Question 37 of 113

1

• Struct type constructors include the set (T), list (T), bag(T), array(T), and dictionary (K,T) type constructors.

Select one of the following:

True
False

Explanation

Question 38 of 113

1

• Three major differences between the relational and object database design.

Select one or more of the following:

• In ODB design a binary relationship can be declared in one direction or both. If attributes are included in both directions, there is a potential problem with redundancy.
• In ODB design a binary relationship can be declared in one direction or both. If attributes are included in both directions, there is no any problem
• In an ODB, operations must be defined early since they are part of the classes specifications. In RDBs, operations may not be defined until implementation
• In RDB inheritance is built into the model; ODBs do not have built-in constructs for inheritance.
• In an RDB, operations must be defined early since they are part of the class specifications. In an ODB, operations may not be defined until implementation
• In ODB inheritance is built into the model; RDBs do not have built-in constructs for inheritance.

Explanation

Question 39 of 113

1

• The typical mechanisms for making an object an object persistent are naming and reachability.

Select one of the following:

True
False

Explanation

Question 40 of 113

1

• The main property required of an OID is that it be immutable (should not change).

Select one of the following:

True
False

Explanation

Question 41 of 113

1

• _____ inheritance occurs when a subtype inherits only some of the functions of a supertype.

Select one of the following:

• Generalisation
• Complete encapsulation
• Conditional
• Selective

Explanation

Question 42 of 113

1

• In operator overloading (or polymorphism), an operation name may refer to several distinct implementations, depending on the type of object it is applied to.

Select one of the following:

True
False

Explanation

Question 43 of 113

1

• In ______ all operations that can be applied to an object must be predefined.

Select one of the following:

• Half encapsulation
• Complete encapsulation
• Object identifier
• Feedback loop

Explanation

Question 44 of 113

1

• The implementation of an operation is called its signature.

Select one of the following:

True
False

Explanation

Question 45 of 113

1

• A subtype is used when a new type is needed that is similar but not identical to an already defined type.

Select one of the following:

True
False

Explanation

Question 46 of 113

1

• The dictionary constructor creates a collection of two tupes (K,V) where the value of a key K can be used to retrieve the can be used to retrieve the corresponding value V.

Select one of the following:

True
False

Explanation

Question 47 of 113

1

• An ODMS provides a unique identity to each independent object in the database via a unique, system-generated ____.

Select one of the following:

• Selective
• Complete encaplsulation
• Object identifier

Explanation

Question 48 of 113

1

• An object typically has three components: state, timing, and behavior

Select one of the following:

True
False

Explanation

Question 49 of 113

1

• The 80-20 rule suggests that 80% of the workload is presented by 20% of the most frequently used transactions, which govem the physical database design.

Select one of the following:

True
False

Explanation

Question 50 of 113

1

• The phases (or activities) of the life cycle are not strictly in sequence; ______ are common among and within the phases of the life cycle.

Select one of the following:

• One-shot
• Requirements collection
• Feedback loop
• View integration

Explanation

Question 51 of 113

1

• In the _____ approach to schema design, a scheme is designed for each user group or application based phase, these schemas are merged into a global conecptual schema.

Select one of the following:

• Requirements analysis
• Feedback loops
• Feasibility analysis
• One-shot
• View integration

Explanation

Question 52 of 113

1

• A large database typically has large transaction volumes and rates, is used in service sector industries, and runs 24/7

Select one of the following:

True
False

Explanation

Question 53 of 113

1

• Many organizations use data dictionary systems (information repositories) to manage meta-data, i.e., data that describes the database structure, constraints, applications, authorizations, users, and so forth.

Select one of the following:

True
False

Explanation

Question 54 of 113

1

• What are the three goals of database design?

Select one or more of the following:

a) Satisfy the information content requirements of the generalised users and applications.
• Support result
• Provide a natural and easy-to-understand structuring of the information.
• Support processing requirements and any performance objectives.
• Satisfy the information content requirements ofthe specified users and applications.
• Provide a comlicated structuring of the information.

Explanation

Question 55 of 113

1

• _______ involves interacting with potential users and user groups to identify their particular problems and needs.

Select one of the following:

• view-integration
• requirements collection and analysis
• feasibility analysis
• one-shot
• feedback loop

Explanation

Question 56 of 113

1

• A transaction processing system can be characterized as one with several dozen gigabytes of data and a schema with more than 30 or 40 distinct entity types

Select one of the following:

True
False

Explanation

Question 57 of 113

1

• Identify the three criteria to guide the choice of physical database design options

Select one or more of the following:

• Space utisilation
• Availability of vendor services
• Transaction throughput
• Response time
• Familiarity of personnel with the system

Explanation

Question 58 of 113

1

• Identify the three factors to consider in choosing one DBMS over another

Select one or more of the following:

• Space utisilation
• Organization-wide adoption of a certain philosophy (data model, vendor, methodology, tools)
• Availability of vendor services
• Transaction throughput
• Response time
• Familiarity of personnel with the system

Explanation

Question 59 of 113

1

• _____ is concerned with analyzing potential application areas, identifying the economics of information gathering and dissemination, performing preiliminary cost-benefit studies, determining the complexity of data and processes, and setting up priorities among applications.

Select one of the following:

• Feasibility analysis
• Requirements collection and analysis
• View integration
• One-shot
• Feedback loops

Explanation

Question 60 of 113

1

• The initial requirements can be expected to be formal, complete, consistent, and correct.

Select one of the following:

True
False

Explanation

Question 61 of 113

1

• In the ______ schema design approach, the requirements from the different stakeholders are merged into a single set of requirements before the schema design begins.

Select one of the following:

• Requirements collection
• Feedback loop
• Centralized (or one-shot)
• Requirements analysis

Explanation

Question 62 of 113

1

• What two things does minimizing redundancy imply?

Select one or more of the following:

• Reducing the need for multiple updates to maintain consistency across multiple copies of the same information.
• Reducing the redundant information in tuples.
• Making sure the semantics of the attributes is clear in the schema
• Minimizing redundant storage of the same information
• Disallowing the possibility of generating spurious tuples

Explanation

Question 63 of 113

1

• Third normal form (3NF): R is 2NF and all non-prime attributes are transively dependent on the primary key.

Select one of the following:

True
False

Explanation

Question 64 of 113

1

• First normal from (1NF): the domain of an attribute must include only atomic (simple, indivisible, scalar) values and the value of any attribute ina tuple must be a single value from the domain of that attribute.

Select one of the following:

True
False

Explanation

Question 65 of 113

1

A functional dependency is a property of the relation schema R not of a particular legal relation state r or R, therefor it must understands the semantics of the attributes of R.

Select one of the following:

True
False

Explanation

Question 66 of 113

1

Second normal form (2NF): R is 1NF and every non-prime attribute A in R is fully functionally dependent on the primary key of R

Select one of the following:

True
False

Explanation

Question 67 of 113

1

What are four informal guidelines that may be used to measure the quality of a relation schema design?

Select one or more of the following:

Reducing the need for multiple updates to maintain consistency across multiple copies of the same information.
• Disallowing the possibility of generating spurious tuples.
• Reducing the redundant information in tuples
• Reducing the NULL values in tuples
• Making sure the semantics of the attributes is clear in the schema
• Minimizing redundant storage of the same information

Explanation

Question 68 of 113

1

Normalization of data can be considered a process of analyzing the given relation schemas based on their functional dependencies and primary keys to achieve closure on the domain space

Select one of the following:

True
False

Explanation

Question 69 of 113

1

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 perticipating entity types (their combination in S is the composite primary key of S).

Select one of the following:

True
False

Explanation

Question 70 of 113

1

The symbol σ (sigma) is used to denote the SELECT operator in the relational algebra

Select one of the following:

True
False

Explanation

Question 71 of 113

1

A EQUIJOIN uses any of the comparison operators =, <, ≤, >, ≥, or ≠.

Select one of the following:

True
False

Explanation

Question 72 of 113

1

The symbol π (pi) is used to denote the PROJECT operation in the relational algebra.

Select one of the following:

True
False

Explanation

Question 73 of 113

1

A THETA JOIN uses the comparison operator =

Select one of the following:

True
False

Explanation

Question 74 of 113

1

SQL is both a data definition language (DDL) and a data manipulation language (DML).

Select one of the following:

True
False

Explanation

Question 75 of 113

1

A key uniquely identifies a tuple in a relation

Select one of the following:

True
False

Explanation

Question 76 of 113

1

When the DELETE operation violates a contraint, the deletion must be rejected.

Select one of the following:

True
False

Explanation

Question 77 of 113

1

Semantic integrity constarint may be enforced using mechanisms called triggers and assertions.

Select one of the following:

True
False

Explanation

Question 78 of 113

1

If a multi-table query refers to two or more attributes with the same name, we must qualify the attribute name with the table name, e.g., TABLE.Attribute, to prevent ambiguity.

Select one of the following:

True
False

Explanation

Question 79 of 113

1

A relation schema may only have one key.

Select one of the following:

True
False

Explanation

Question 80 of 113

1

Tuples in a relation are ordered.

Select one of the following:

True
False

Explanation

Question 81 of 113

1

The DELETE operation can violate referential integrity.

Select one of the following:

True
False

Explanation

Question 82 of 113

1

The INSERT operation can violate domain constraints, key constraints, entity integrity, or referential integrity.

Select one of the following:

True
False

Explanation

Question 83 of 113

1

The theortical basis of the relation data model is set theory and first-order predicate logic.

Select one of the following:

True
False

Explanation

Question 84 of 113

1

Attributes that represent the same real-world concept must have identical names in different relations.

Select one of the following:

True
False

Explanation

Question 85 of 113

1

When the INSERT operation violates a constraint, the default option is to reject the insertion.

Select one of the following:

True
False

Explanation

Question 86 of 113

1

Attributes must have unique domains.

Select one of the following:

True
False

Explanation

Question 87 of 113

1

NULL values may mean value unknown, value exits but is not available, attribute does not apply to this tuple (value undefined).

Select one of the following:

True
False

Explanation

Question 88 of 113

1

All tuples in a relation must be distinct.

Select one of the following:

True
False

Explanation

Question 89 of 113

1

The $d->query function takes an SQL command as its string argument and sends it to the database server for execution.

Select one of the following:

True
False

Explanation

Question 90 of 113

1

The _____ is a collection of several libraries of functions for enhancing PHP.

Select one of the following:

DBMS
PHP Extension and Application Repository (PEAR)
MYSQL
PHP SQL

Explanation

Question 91 of 113

1

The _____ variable is similar to cursor and iterator variables.

Select one of the following:

$d->query
post
$r

Explanation

Question 92 of 113

1

The abend function can be used to terminate a PHP program if there is an error.

Select one of the following:

True
False

Explanation

Question 93 of 113

1

The PHP function $d->nextID creates a sequence of unique values for a particular table.

Select one of the following:

True
False

Explanation

Question 94 of 113

1

Creating a database design that only stores each logical data item in only one place in the database

Select one of the following:

Normalization
Relational data model
Data abstraction
Redundancy

Explanation

Question 95 of 113

1

Stores catalog information about schemas and constraints, design decisions, usage standards, application program descriptions, and user information

Select one of the following:

Data dictionary (or data repository system or information repository)
Relational data model
Atomicity property
Data abstraction

Explanation

Question 96 of 113

1

Data that is derived from the database files but not explicitly stored

Select one of the following:

Relationship
Relational data model
Virtual data
Virtual date

Explanation

Question 97 of 113

1

Represents an association among two or more entities

Select one of the following:

. Relationship
Relational data model
Data abstraction
Redundancy

Explanation

Question 98 of 113

1

Represents a database as a collection of tables, where each table can be stored as a separate file

Select one of the following:

Data abstraction
Atomicity property
Redundancy
Relational data model

Explanation

Question 99 of 113

1

Ensures that either all the database operations in a transaction are executed or none are

Select one of the following:

Atomicity property
Atomic property
Redundancy
Data abstraction

Explanation

Question 100 of 113

1

Storing the same data multiple times

Select one of the following:

Redundancy
Data abstraction
Relationship
Virtual data

Explanation

Question 101 of 113

1

Characteristic that allows program-data independence and program-operation independence

Select one of the following:

Redundancy
Data abstraction
Relationship
Relational data model

Explanation

Question 102 of 113

1

Choose correct answer

Select one of the following:

Explanation

Question 103 of 113

1

Choose correct answer!!

Select one of the following:

Explanation

Question 104 of 113

1

Choose one

Select one of the following:

Explanation

Question 105 of 113

1

is typically used to loop over the tuples in a query result

Select one of the following:

cursor
named
positional
Impedance mismatch

Explanation

Question 106 of 113

1

iterator is associated with a query result in SQLJ by listing the attribute names and types that appear in the query

Select one of the following:

named
cursor
Impedance mismatch
positional

Explanation

Question 107 of 113

1

iterator lists only the attribute types that appear in a query result in SQLJ.

Select one of the following:

positional
Impedance mismatch
named
cursor

Explanation

Question 108 of 113

1

is the term used to refer to the problems that occur because of differences between the database model and language model

Select one of the following:

Impedance mismatch
positional
named
cursor

Explanation

Question 109 of 113

1

Used to choose a subset of the tuples from a relation that satisfies a selection condition

Select one of the following:

• LEFT OUTER JOIN
• SELECT
• PROJECT
• JOIN
• INTERSECTION

Explanation

Question 110 of 113

1

Selects certain columns from the table and discards the other columns

Select one of the following:

• PROJECT
• SELECT
• LEFT OUTER JOIN
• JOIN
• INTERSECTION

Explanation

Question 111 of 113

1

= R S keeps every tuple in the first (left) relation R; if no matching tuples is found in S, then the attributes of S in the join filled with NULL values

Select one of the following:

• LEFT OUTER JOIN
• SELECT
• PROJECT
• JOIN
• INTERSECTION

Explanation

Question 112 of 113

1

R S in the relational algebra combines related tuples in R and S

Select one of the following:

• JOIN
• INTERSECTION
• LEFT OUTER JOIN
• PROJECT
• SELECT

Explanation

Question 113 of 113

1

R S in the relational algebra includes all tuples in both R and S

Select one of the following:

• JOIN
• INTERSECTION
• LEFT OUTER JOIN
• PROJECT
• SELECT

	Created by Жарас Мергазы over 6 years ago

Quiz on sdp 6 , created by Жарас Мергазы on 16/12/2017.

Question 1 of 113

The PEAR DB functions can be accessed using DB::<function_name>.

Select one of the following:

Explanation

Question 2 of 113

The string argument of the function for connecting to a database is of the format <DBMS software>://<user account>:<password>@<database server>

Select one of the following:

Explanation

Question 3 of 113

The PEAR DB functon for connecting to a database is called DB::linkto database('string').

Select one of the following:

Explanation

Question 4 of 113

• The DBMS software in <DBMS software>://<user account>:<password>@<database server> stands for the particular DBMS software package being connected to: for example mysqli for versions of MySQL starting with version 4.1.2

Select one of the following:

Explanation

Question 5 of 113

• The PEAR DB function DB::is Error can be used to determine whether any database access operation was successful or not.

Select one of the following:

Explanation

Question 6 of 113

• In PHP, an _____ array provides pairs of key=>value elements; the value of an element is referenced through its key and all key values in a particular array must be unique.

Select one of the following:

Explanation

Question 7 of 113

• Multi-line PHP comments start with // and end with #.

Select one of the following:

Explanation

Question 8 of 113

• PHP written in C and usually comes installed with Unix: for other operating systems, the PHP interpreter can be downloaded from http://www.php.net

Select one of the following:

Explanation

Question 9 of 113

• The PHP start tag is <?php and end the tag is ?>.

Select one of the following:

Explanation

Question 10 of 113

• Web pages, where part of the information is extracted from databases or other data source, are called dynamic Web pages

Select one of the following:

Explanation

Question 11 of 113

• In PHP, a ____ array associates a numeric index with each element in the array

Select one of the following:

Explanation

Question 12 of 113

• PHP variable names start with a $ sign and can include characters, numbers, and the underscore character

Select one of the following:

Explanation

Question 13 of 113

• Interpolating variables occurs only within single-quoted strings.

Select one of the following:

Explanation

Question 14 of 113

• PHP programs are executed on the client.

Select one of the following:

Explanation

Question 15 of 113

• The auto-global predefined PHP variable $_POST is an array that holds all the values entered through form parameters.

Select one of the following:

Explanation

Question 16 of 113

• JDBC does not distinguish between queries that return single tuples and those that return multiple tuples.

Select one of the following:

Explanation

Question 17 of 113

• The JDBC _____ libraries are called java.sql.*

Select one of the following:

Explanation

Question 18 of 113

• What are the advantages and disadvantages of the embedded SQL approach.

Select one or more of the following:

Explanation

Question 19 of 113

• The use of function calls is a more dynamic approach for database programming than embedded SQL.

Select one of the following:

Explanation

Question 20 of 113

• A _____ object is similar to a cursor in embedded SQL and an iterator in SQLJ.