76 + Interview Questions in Query Processing Techniques in Database Management Page 2 InterviewSolution

51.	We use ______________ name PL/SQL program objects and units.(a) Lexical Units(b) Literals(c) Delimiters(d) IdentifiersI got this question in quiz.My question comes from Advanced Query Optimization in portion Query Processing Techniques of Database Management
Answer» Right answer is (d) Identifiers The BEST I can EXPLAIN: The database object NAME is referred to as its IDENTIFIER.

Discussion

52.	Which of the following fixed database roles can add or remove user IDs?(a) db_accessadmin(b) db_securityadmin(c) db_setupadmin(d) db_sysadminThe question was asked in an interview.My doubt stems from Transformation of Relational Expressions topic in section Query Processing Techniques of Database Management
Answer» Right option is (a) db_accessadmin Best explanation: The db_accessadmin role MANAGES SECURITY, but HANDLES access to the database, as the NAME implies.

Discussion

53.	Which of the following schemas does define a view or views of the database for particular users?(a) Internal schema(b) Conceptual schema(c) Physical schema(d) External schemaI have been asked this question during an internship interview.The doubt is from Query Processing in division Query Processing Techniques of Database Management
Answer» The correct option is (d) EXTERNAL SCHEMA Explanation: An externally-defined schema can provide access to tables that are MANAGED on any POSTGRESQL, Microsoft SQL SERVER, SAS, Oracle, or MySQL database.

Discussion

54.	Which is a join condition contains an equality operator:(a) Equijoins(b) Cartesian(c) Both Equijoins and Cartesian(d) None of the mentionedI have been asked this question during an interview.I'm obligated to ask this question of Join Operations topic in division Query Processing Techniques of Database Management
Answer» The correct choice is (a) Equijoins Easiest explanation - An equi-join is a SPECIFIC TYPE of comparator-based join, that USES only EQUALITY COMPARISONS in the join-predicate.

Discussion

55.	___________ combines the data manipulating power of SQL with the data processing power of Procedural languages.(a) PL/SQL(b) SQL(c) Advanced SQL(d) PQLI had been asked this question at a job interview.I'm obligated to ask this question of Advanced Query Optimization in portion Query Processing Techniques of Database Management
Answer» CORRECT ANSWER is (a) PL/SQL Explanation: PL/SQL is an IMPERATIVE 3GL that was designed specifically for the seamless PROCESSING of SQL commands.

Discussion

56.	Which normal form is considered adequate for normal relational database design?(a) 2NF(b) 5NF(c) 4NF(d) 3NFI have been asked this question during an interview.I'd like to ask this question from Materialized Views topic in portion Query Processing Techniques of Database Management
Answer» The correct answer is (d) 3NF The best I can explain: A relational DATABASE table is often described as “normalized” if it is in the Third Normal Form because most of the 3NF TABLES are FREE of insertion, update, and deletion ANOMALIES.

Discussion

57.	How inserting data through stored procedure do reduces network traffic and increase database performance?(a) Stored procedure can accept parameter(b) Permission check is not required(c) The execution plan is stored in the cache after it was executed the first time(d) None of the mentionedI have been asked this question in quiz.My enquiry is from Estimating Statistics of Expression Results in portion Query Processing Techniques of Database Management
Answer» The correct option is (c) The execution plan is stored in the cache after it was executed the FIRST time Easiest explanation - A relational database table is OFTEN DESCRIBED as “normalized” if it is in the Third Normal Form because most of the 3NF tables are free of insertion, UPDATE, and deletion ANOMALIES.

Discussion

58.	Which product is returnedin a join query have no join condition:(a) Equijoins(b) Cartesian(c) Both Equijoins and Cartesian(d) None of the mentionedThis question was posed to me in examination.My doubt is from Join Operations in portion Query Processing Techniques of Database Management
Answer» Correct option is (b) Cartesian For explanation: A Cartesian COORDINATE system is a coordinate system that specifies each POINT uniquely in a plane by a pair of numerical coordinates.

Discussion

59.	The ___ algorithm scans each index for pointers to tuples that satisfy an individual condition.(a) A2(b) A4(c) A9(d) A6This question was posed to me in my homework.The query is from Selection Operation topic in section Query Processing Techniques of Database Management
Answer» Correct CHOICE is (C) A9 The EXPLANATION is: A9 – Conjunctive selection by an INTERSECTION of identifiers.

Discussion

60.	Search algorithms that use an index are referred to as(a) Index Search(b) Linear search(c) File scan(d) Access pathsThis question was addressed to me in an international level competition.I'd like to ask this question from Selection Operation topic in section Query Processing Techniques of Database Management
Answer» CORRECT ANSWER is (a) Index Search To explain: Selection predicates are USED to guide in the choice of the index to USE in processing the query.

Discussion

61.	Each operation in a demand-driven pipeline can be implemented as an ____ that provides the following functions: open(), next(), and close().(a) Demand(b) Pipeline(c) Iterator(d) All of the mentionedI have been asked this question in an international level competition.This intriguing question originated from Evaluation of Expressions topic in portion Query Processing Techniques of Database Management
Answer» Correct answer is (c) Iterator The BEST EXPLANATION: After a call to OPEN(), each call to next() RETURNS the next output tuple of the operation.

Discussion

62.	The complexity of a linear search algorithm is(a) O(n)(b) O(log n)(c) O(n2)(d) O(n log n)I got this question by my school principal while I was bunking the class.My question is based upon Sorting topic in portion Query Processing Techniques of Database Management
Answer» The correct answer is (a) O(n) Explanation: It refers to n values COMPLEXITY in the ALGORITHM which can be reduced by choosing the other ALGORITHMS.

Discussion

63.	The space factor when determining the efficiency of an algorithm is measured by(a) Counting the maximum memory needed by the algorithm(b) Counting the minimum memory needed by the algorithm(c) Counting the average memory needed by the algorithm(d) Counting the maximum disk space needed by the algorithmThe question was posed to me in final exam.The above asked question is from Sorting topic in chapter Query Processing Techniques of Database Management
Answer» Correct answer is (a) COUNTING the maximum MEMORY needed by the algorithm Easiest EXPLANATION - Time complexity MAINTAINS the maximum time needed.

Discussion

64.	A collection of data designed to be used by different people is called a/an(a) Organization(b) Database(c) Relationship(d) SchemaThis question was posed to me in an online quiz.This is a very interesting question from Query Processing topic in chapter Query Processing Techniques of Database Management
Answer» The correct choice is (b) DATABASE For explanation: Database is a collection of RELATED TABLES.

Discussion

65.	Which of the following are the process of selecting the data storage and data access characteristics of the database?(a) Logical database design(b) Physical database design(c) Testing and performance tuning(d) Evaluation and selectingI got this question during an interview for a job.This intriguing question originated from Query Processing in section Query Processing Techniques of Database Management
Answer» The correct choice is (b) PHYSICAL DATABASE design For explanation: The physical design of the database optimizes performance while ensuring DATA INTEGRITY by avoiding unnecessary data redundancies.

Discussion

66.	The results of each intermediate operation are created and then are used for evaluation of the next-level operations. This is called(a) Materialized evaluation(b) Expression evaluation(c) Tree evaluation(d) Tree materializationThis question was posed to me in quiz.This interesting question is from Evaluation of Expressions topic in section Query Processing Techniques of Database Management
Answer» Correct OPTION is (a) Materialized EVALUATION Easy explanation - The COST of a materialized evaluation is not SIMPLY the sum of the costs of the operations involved.

Discussion

67.	If no header is specified, the block is said to be an _______________ PL/SQL block.(a) Strong(b) Weak(c) Empty(d) AnonymousThe question was posed to me by my college professor while I was bunking the class.I'd like to ask this question from Advanced Query Optimization in portion Query Processing Techniques of Database Management
Answer» RIGHT ANSWER is (d) Anonymous Easy EXPLANATION - The terms literal and constant value are SYNONYMOUS and refer to a FIXED data value.

Discussion

68.	The iterator maintains the __________ of its execution in between calls so that successive next() requests receive successive result tuples.(a) State(b) Transition(c) Rate(d) BlockThe question was asked in unit test.The doubt is from Evaluation of Expressions in section Query Processing Techniques of Database Management
Answer» Correct choice is (a) State The EXPLANATION is: The FUNCTION close() TELLS an ITERATOR that no more tuples are REQUIRED.

Discussion

69.	The time factor when determining the efficiency of an algorithm is measured by(a) Counting microseconds(b) Counting the number of key operations(c) Counting the number of statements(d) Counting the kilobytes of algorithmThe question was asked in final exam.The question is from Sorting in portion Query Processing Techniques of Database Management
Answer» The CORRECT OPTION is (b) Counting the number of key operations Easiest EXPLANATION - The operations taking PLACE with the TIME and space is counted.

Discussion

70.	Which algorithm uses equality comparison on a key attribute with a primary index to retrieve a single record that satisfies the corresponding equality condition.(a) A2(b) A4(c) A5(d) A6I got this question in an online quiz.Enquiry is from Selection Operation topic in division Query Processing Techniques of Database Management
Answer» The correct choice is (a) A2 The EXPLANATION is: A2 – primary INDEX, EQUALITY on key.

Discussion

71.	A table can be logically connected to another table by defining a(a) Super key(b) Candidate key(c) Primary key(d) Unique keyI got this question during an interview.This key question is from Query Processing in chapter Query Processing Techniques of Database Management
Answer» The correct option is (c) Primary key For EXPLANATION: A SUPERKEY is a combination of ATTRIBUTES that can be uniquely USED to identify a DATABASE record.

Discussion

72.	Which are the join types in join condition:(a) Cross join(b) Natural join(c) Join with USING clause(d) All of the mentionedI have been asked this question in an internship interview.This intriguing question originated from Join Operations topic in portion Query Processing Techniques of Database Management
Answer» Correct choice is (d) All of the mentioned Easy EXPLANATION - INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL JOIN, EQUIJOIN are the types of joins.

Discussion

73.	Which of the following is an attribute that can uniquely identify a row in a table?(a) Secondary key(b) Candidate key(c) Foreign key(d) Alternate keyI had been asked this question in an online quiz.This intriguing question comes from Query Processing in portion Query Processing Techniques of Database Management
Answer» The correct OPTION is (b) Candidate KEY Explanation: A Candidate Key can be any column or a COMBINATION of columns that can QUALIFY as unique key in database.

Discussion

74.	Which of the following statements is/are not true for SQL profiler?(a) Enables you to monitor events(b) Check if rows are being inserted properly(c) Check the performance of a stored procedure(d) None of the mentionedThe question was posed to me during an interview for a job.Enquiry is from Estimating Statistics of Expression Results in division Query Processing Techniques of Database Management
Answer» RIGHT option is (c) Check the performance of a STORED procedure For EXPLANATION: Stored procedures are like functions which do not RETURN values.

Discussion

75.	Which oracle is the join condition is specified using the WHERE clause:(a) Oracle 9i(b) Oracle 8i(c) Pre-oracle 9i(d) Pre-oracle 8iI got this question in an online quiz.Query is from Join Operations in division Query Processing Techniques of Database Management
Answer» Correct option is (C) Pre-oracle 9i To EXPLAIN: Oracle 9i is a VERSION of the Oracle Database. The i STANDS for “INTERNET” to indicate that 9i is “Internet ready”.

Discussion

76.	In a ____________ the system scans each file block and tests all records to see whether they satisfy the selection condition.(a) Index Search(b) Linear search(c) File scan(d) Access pathsThis question was posed to me during an interview.The above asked question is from Selection Operation topic in division Query Processing Techniques of Database Management
Answer» Right answer is (b) Linear search Easy explanation - An initial SEEK is required to ACCESS the FIRST block of the FILE.

Discussion

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We use ______________ name PL/SQL program objects and units.(a) Lexical Units(b) Literals(c) Delimiters(d) IdentifiersI got this question in quiz.My question comes from Advanced Query Optimization in portion Query Processing Techniques of Database Management

Which normal form is considered adequate for normal relational database design?(a) 2NF(b) 5NF(c) 4NF(d) 3NFI have been asked this question during an interview.I'd like to ask this question from Materialized Views topic in portion Query Processing Techniques of Database Management

Which product is returnedin a join query have no join condition:(a) Equijoins(b) Cartesian(c) Both Equijoins and Cartesian(d) None of the mentionedThis question was posed to me in examination.My doubt is from Join Operations in portion Query Processing Techniques of Database Management

The ___ algorithm scans each index for pointers to tuples that satisfy an individual condition.(a) A2(b) A4(c) A9(d) A6This question was posed to me in my homework.The query is from Selection Operation topic in section Query Processing Techniques of Database Management

The complexity of a linear search algorithm is(a) O(n)(b) O(log n)(c) O(n2)(d) O(n log n)I got this question by my school principal while I was bunking the class.My question is based upon Sorting topic in portion Query Processing Techniques of Database Management

A table can be logically connected to another table by defining a(a) Super key(b) Candidate key(c) Primary key(d) Unique keyI got this question during an interview.This key question is from Query Processing in chapter Query Processing Techniques of Database Management

Which oracle is the join condition is specified using the WHERE clause:(a) Oracle 9i(b) Oracle 8i(c) Pre-oracle 9i(d) Pre-oracle 8iI got this question in an online quiz.Query is from Join Operations in division Query Processing Techniques of Database Management