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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 201. |
What is the difference between flash memory and main memory?(a) Data is retained in flash memory(b) Data access is faster in flash memory(c) Data storage is very large in flash memory(d) None of the mentioned |
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Answer» Correct option is (a) Data is retained in flash memory To elaborate: Data is retained in flash memory. Power losses do not affect the data stored in flash memory. |
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| 202. |
Which of the following is/are a function of dynamic SQL?(a) Allowing a program to construct an SQL query in a character string(b) Submitting the query(c) Retrieving the result into the program variables a tuple at a time(d) All of the mentioned |
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Answer» The correct option is (d) All of the mentioned Easy explanation: Dynamic SQL allows the program to construct the queries in character string format, it submits them, and then retrieves the data into the program variables one tuple at a time. |
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| 203. |
Which of the following is included in the operational mechanism of the index locking protocol?(a) Every transaction must have at least one index(b) A transaction that performs a lookup must acquire a shared lock on all the index leaf nodes that it accesses(c) The rule of the two phase locking mechanism must be observed(d) All of the mentioned |
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Answer» Right choice is (d) All of the mentioned The best explanation: The operational mechanism of the index locking protocol includes, every transaction must have at least one index. A transaction that performs lookup must acquire a shared lock on all the index leaf nodes that it accesses. The rule of the two phase locking mechanism must be followed. |
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| 204. |
To prevent the phantom phenomenon, _______ is used(a) Key value locking(b) Next key locking(c) Previous key locking(d) None of the mentioned |
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Answer» Right option is (b) Next key locking The explanation is: The failure of a system to prevent a non serialized tuple when two transactions conflict with each other is called as phantom phenomenon. To prevent the phantom phenomenon, the next key locking is used. |
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| 205. |
Which of the following information does an SQL DDL not specify?(a) The schema for each relation(b) The integrity constraints(c) The operations on the tuples(d) The security and authorization information for each relation |
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Answer» Correct choice is (c) The operations on the tuples Explanation: The SQL DDL does not specify the operations that are supposed to be made on the tuples. DDL means Data definition language, hence it does not include the operations made. |
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| 206. |
The scheme that controls the interaction between executing transactions is called as _____(a) Concurrency control scheme(b) Multiprogramming scheme(c) Serialization scheme(d) Schedule scheme |
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Answer» Correct choice is (a) Concurrency control scheme Explanation: The scheme that controls the interaction between executing transactions is called as concurrency control scheme. |
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| 207. |
A transaction can proceed only after the concurrency control manager ________ the lock to the transaction(a) Grants(b) Requests(c) Allocates(d) None of the mentioned |
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Answer» The correct answer is (a) Grants Explanation: A transaction can proceed only after the concurrency control manager grants the lock to the transaction. |
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| 208. |
Which of the following data types does the SQL standard not support?(a) char(n)(b) String(n)(c) varchar(n)(d) float(n) |
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Answer» Right option is (b) String(n) To explain I would say: The SQL standard does not support String(n) but it supports char, varchar and float. |
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| 209. |
Which of the following is a privilege in SQL standard?(a) select(b) insert(c) update(d) All of the mentioned |
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Answer» Right choice is (d) All of the mentioned Easy explanation: The SQL standard includes the privileges select, insert, update and delete. This privilege set can be granted or revoked among the users. |
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| 210. |
Which of the following are the advantages of transaction concurrency?(a) Increased throughput(b) Increased utilization(c) Reduces average response time(d) All of the mentioned |
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Answer» Right answer is (d) All of the mentioned The explanation: Concurrency in transactions allow increased throughput, utilization. They also reduce average response time. |
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| 211. |
The execution sequences in concurrency control are termed as ________(a) Serials(b) Schedules(c) Organizations(d) Time tables |
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Answer» Right answer is (b) Schedules Easy explanation: The execution sequences in concurrency control are known as schedules. |
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| 212. |
What is an NVRAM?(a) RAM which is non-volatile in nature(b) RAM whose data is not lost during power failures(c) RAM that significantly speeds up data transfers(d) All of the mentioned |
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Answer» Right answer is (d) All of the mentioned Easiest explanation: A non-volatile random access memory or NVRAM is the one which is non-volatile, data is retained during power failure and which considerably speeds up the disk writes. |
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| 213. |
Which of the following is true about file header?(a) It is allocated at the beginning of the file(b) It has information about the file(c) It generally contains the address of the first record in it(d) All of the mentioned |
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Answer» The correct choice is (d) All of the mentioned Best explanation: A file header is a certain number of bytes allocated at the beginning of the file. It contains a variety of information about the file and it can be used to point the first record by storing the address of the first record in it. |
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| 214. |
How can variable length records arise in a file(a) Storage of multiple record types in a file(b) Record types that allow variable lengths for one or more fields(c) Record types that allow repeating fields, such as arrays or multisets(d) All of the mentioned |
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Answer» Right choice is (d) All of the mentioned For explanation: Variable length records arise in a system in several ways like, Storage of multiple record types in a file. Record types that allow variable lengths for one or more fields. Record types that allow repeating fields, such as arrays or multisets. |
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| 215. |
The header in the slotted page structure does not contain which of the following data?(a) The number of record entries in the header(b) The end of free space in a block(c) The size of all the records put together in the header(d) An array containing location and size of each record |
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Answer» Right option is (c) The size of all the records put together in the header The best explanation: The header in the slotted page structure does not contain the size of all the records put together in the header but it contains the number of record entries, the end of free space and an array containing location and size of each record. |
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| 216. |
What is the approximate storage capacity of CDs in MB(a) 300(b) 700(c) 1100(d) 1500 |
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Answer» The correct answer is (b) 700 The best explanation: s: CDs generally have a storage capacity of 700 Megabytes and DVDs have a storage capacity of around 4.7 Gigabytes. |
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| 217. |
Which of the following is not a classification of storage(a) Volatile storage(b) Nonvolatile storage(c) Stable storage(d) None of the mentioned |
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Answer» Right answer is (d) None of the mentioned Best explanation: Volatile storage, non-volatile storage and stable storage are three different classifications of storage. Volatile storage is the least secure whereas stable storage is the most secure among them. |
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| 218. |
The process of maintaining views up to date is called _________(a) View maintenance(b) View updating(c) View materialization(d) View isolation |
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Answer» Correct option is (a) View maintenance To explain I would say: The process of maintaining views up to date is called View maintenance. View maintenance can be done immediately when any of the views is updated. |
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| 219. |
If the actual relations used in the view definition change, the view is updated immediately. Such views are called _________(a) Instant views(b) Instantaneous views(c) Materialistic views(d) Materialized views |
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Answer» Correct option is (d) Materialized views The explanation is: If the actual relations used in the view definition change, the view is updated immediately. Such views are called Materialized views. Materialized views help to keep the database up-to-date. |
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| 220. |
If a failure has occurred in the midst of a transfer, it is called as _________(a) Successful completion(b) Partial failure(c) Total failure(d) None of the mentioned |
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Answer» Correct choice is (b) Partial failure For explanation: If a failure has occurred in the midst of a transfer, it is called as partial failure. After a partial failure, the destination has incorrect information. |
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| 221. |
Which of the following is an issue that needs to be considered while choosing an indexing technique?(a) Frequency of insertion and deletion(b) Data types of the data(c) Number of items in the relation(d) None of the mentioned |
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Answer» The correct answer is (a) Frequency of insertion and deletion For explanation I would say: The frequency of insertion and deletion has to be taken into consideration while choosing an indexing technique. The frequency of insertion and deletion determines the hash index. |
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| 222. |
The usage of two buffers, with one continuing execution of the algorithm while the other is written is called as __________(a) Double execution(b) Multi tasking(c) Double buffering(d) Double algorithm |
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Answer» Correct option is (c) Double buffering For explanation: The usage of two buffers, with one continuing execution of the algorithm while the other is written is called as Double buffering. This makes the algorithm quicker by performing CPU operations simultaneously with the I/O operations. |
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| 223. |
What are man in the middle attacks?(a) Users are forced to use a second server which causes the attack(b) Users are forced to divert to a fake site where the attack takes place(c) Users are fooled by similar GUI and data is extracted from them.(d) None of the mentioned |
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Answer» The correct option is (b) Users are forced to divert to a fake site where the attack takes place Best explanation: Man in the middle attacks are those attacks in which the users are forced to divert to a fake site where the attack takes place. The fake site is then used to obtain the data from the user. |
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| 224. |
Which of the following keywords is used beside the select clause to explicitly specify that duplicates are not removed?(a) all(b) not unique(c) notnull(d) include |
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Answer» The correct answer is (a) all To elaborate: The “all” keyword is used beside the select clause to explicitly specify that duplicates are not removed. |
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| 225. |
While operating with strings, what does “_ _ _%” match with?(a) A string of three letters(b) A string of at least three letters(c) A string of three words(d) A string of at least three words |
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Answer» Correct option is (a) A string of three letters To explain: The string in the question matches with a string having at least three letters. The first three blank spaces indicate three letters whereas the percentage indicates indefinite spaces after that. |
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| 226. |
Which keyword is used to rename the resulting attribute after the application of the aggregation function?(a) rename(b) as(c) replace(d) to |
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Answer» Correct choice is (b) as For explanation I would say: The “as” keyword is used to rename the resulting attribute after the aggregation function has been applied. Just like any other renaming operation, the as keyword simplifies the name of the relation. |
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| 227. |
The on condition appears at the _______ of the join expression(a) Beginning(b) End(c) Between(d) The on condition is not related to join expression |
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Answer» The correct choice is (b) End Easy explanation: The on condition appears at the end of the join expression. Because it states the condition that the relations under the join operations get matched based on. |
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| 228. |
The system where two independent pieces of data are used to identify a user is called as ______(a) Two system authentication(b) ID password authentication(c) Two factor authentication(d) Multi data authentication |
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Answer» Correct choice is (c) Two factor authentication Best explanation: The system where two independent pieces of data are used to identify a user is called as two-factor authentication. The two factors should not share a common vulnerability. |
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| 229. |
What is the function of the union operation?(a) It combines the results of any two different queries(b) It combines the results of two different queries which have the same set of attributes in the select clause(c) It combines the results of two different queries which have the same condition in the where clause(d) It gives the Cartesian product of the results of any 2 queries |
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Answer» Correct option is (b) It combines the results of two different queries which have the same set of attributes in the select clause Easiest explanation: The union operation combines the results of two different queries which have the same set of attributes in the select clause. It automatically eliminates duplicates. |
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| 230. |
What is the difference between a join and an outer join operation?(a) There is no difference(b) Join preserves a few tuples that are otherwise lost in the outer join(c) Outer join preserves a few tuples that are otherwise lost in the join(d) An outer join can be used only on outer queries whereas a join operation can be used in Subqueries |
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Answer» Correct option is (c) Outer join preserves a few tuples that are otherwise lost in the join For explanation I would say: The outer join operation preserves a few tuples that are otherwise lost in the join operation. The outer join operation preserves the tuples to the right of the operation. |
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| 231. |
Which keyword is used to rename a relation in a query?(a) rename(b) as(c) is(d) to |
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Answer» The correct choice is (b) as To explain: The “as” keyword is used to rename a relation in a query. This is used for convenience as long relation names can reduce readability. |
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| 232. |
The ________ clause is used to list the attributes desired in the result of a query(a) select(b) from(c) where(d) create |
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Answer» Correct answer is (a) select Best explanation: The select clause is used to list the attributes desired in the result of a query. |
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| 233. |
If a1, a2, a3 are attributes in a relation and S is another relation, which of the following is an incorrect specification of an integrity constraint?(a) primary key(a1, a2, a3)(b) primary key(a1)(c) foreign key(a1, a2) references S(d) foreign key(a1, a2) |
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Answer» Right answer is (d) foreign key(a1, a2) Explanation: Whenever the integrity constraint foreign key is mentioned, the attributes that are the foreign keys should always be referenced from the relation in which they are primary keys. |
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| 234. |
Which of the following logical connectives is not included in SQL?(a) and(b) or(c) nor(d) not |
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Answer» Right option is (d) not Best explanation: “not” is not a logical connective included in the SQL. The and, or and nor are logical connectives that are included in SQL. |
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| 235. |
What does the above query do?(a) It gives all the tuples having a distinct dept_name(b) It gives the dept_name attribute values of all tuples without repetition(c) It gives all the dept_name attribute of all the tuples(d) It gives all the tuples having a null value under the dept_name attribute |
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Answer» Correct choice is (b) It gives the dept_name attribute values of all tuples without repetition Best explanation: The distinct keyword is used to explicitly force the elimination of duplicate tuples. Thus, the above query excludes duplicates. |
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| 236. |
What is the function of the intersect operation?(a) It returns the intersection of the results of the results of any two different queries(b) It returns the intersection of the results of two different queries which have the same set of attributes in the select clause(c) It returns the intersection of the results of two different queries which have the same condition in the where clause(d) None of the mentioned |
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Answer» Right answer is (b) It returns the intersection of the results of two different queries which have the same set of attributes in the select clause Easy explanation: The intersect operation returns the intersection of the results of the results of two different queries which have the same set of attributes in the select clause. It automatically eliminates duplicates. |
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| 237. |
Which of the following is an illegal data type in SQL(a) number(b) clob(c) blob(d) lint |
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Answer» Correct choice is (d) lint Explanation: clob and blob are called large object data types. They can be used to store values that can go to the size of gigabytes. Number is used to store the basic integer data type. |
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| 238. |
If we specify multiple relations in the from clause and do not specify any conditions in the where clause, what will the result be?(a) The natural join of both the relations(b) The left outer join of both the relations(c) A syntactical error(d) The Cartesian product of both the relations |
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Answer» Right choice is (d) The Cartesian product of both the relations For explanation I would say: If we specify multiple relations in the from clause and do not specify any conditions in the where clause, the default definition given by the from clause is the Cartesian product of the relations listed in the clause. So it returns all the possible combinations of the tuples of the two relations. |
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| 239. |
What does the natural join operation do?(a) It considers only those pairs of tuples that have the same value on those attributes that appear in the schemas of both relations(b) It considers only those pairs of tuples that have the same value on at least one of the attributes that appear in the schemas of both the relations(c) It considers only those pairs of tuples that do not have the same value on those attributes that appear in the schemas of both relations(d) None of the mentioned |
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Answer» Right option is (a) It considers only those pairs of tuples that have the same value on those attributes that appear in the schemas of both relations To elaborate: The natural join operation considers only those pairs of tuples that have the same value on those attributes that appear in the schemas of both the relations. The natural join operation operates on 2 relations and gives a relation as the result. |
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| 240. |
The where clause is a predicate involving attributes of the relation in the ______ clause.(a) select(b) from(c) with(d) none of the mentioned |
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Answer» The correct option is (b) from For explanation: The “from” clause contains the attribute names on which the “which” clause can be used on. |
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| 241. |
What is the function of the except operation?(a) It excludes all the results present in both the queries(b) It includes the results of the second query but excludes the results of the first query(c) It includes the results of the first query but excludes the results of the second query(d) It includes all the results of both queries but removes duplicates |
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Answer» Right answer is (c) It includes the results of the first query but excludes the results of the second query For explanation: The except operation includes the results of the first query but excludes the results of the second query. It automatically eliminates duplicates but if we want to retain duplicates we must use except all in place of except. |
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| 242. |
The URL of the page that had the link that the user clicked to access the page is called as _____(a) Source(b) Linker(c) Leaker(d) Referrer |
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Answer» Correct option is (d) Referrer For explanation I would say: The URL of the page that had the link that the user clicked to access the page is called as referrer. The HTTP protocol allows the server to check the referrer. |
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| 243. |
What is a default value?(a) It is a value that automatically creates a primary key(b) It is a value that cannot be altered during insertion of values in the tuple(c) It is a value that is initially loaded into the attribute(d) None of the mentioned |
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Answer» Correct answer is (c) It is a value that is initially loaded into the attribute For explanation: A default value is a value that is initially loaded into the attribute. All the tuples have the default value in the attribute for which it is specified in case any value is not externally specified. |
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| 244. |
A bitmap is _______(a) An array of bits(b) An index of bits(c) A function mapping all the bits of data(d) None of the mentioned |
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Answer» The correct answer is (a) An array of bits Easiest explanation: A bitmap is simply an array of bits. A bitmap can be used for various purposes such as bitmap indexing. |
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| 245. |
Referential integrity constraints are also called as _________(a) Functional dependencies(b) Subset dependencies(c) Superset dependencies(d) Primary dependencies |
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Answer» Correct choice is (b) Subset dependencies The best explanation: Referential integrity constraints are also called as subset dependencies. It is called so because the set of foreign key values in r1 of r2 must be a subset of the set of primary key values in r2. |
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| 246. |
The average time for a transaction to be completed after it has been submitted is called as __________(a) Minimum response time(b) Average response time(c) Average reaction time(d) Minimum reaction time |
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Answer» The correct option is (b) Average response time Explanation: The average time for a transaction to be completed after it has been submitted is called as Average response time. This gets decreased when concurrency is used in transactions. |
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| 247. |
A transaction that has not been completed successfully is called as _______(a) Compensating transaction(b) Aborted transaction(c) Active transaction(d) Partially committed transaction |
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Answer» Correct option is (b) Aborted transaction For explanation I would say: Aborted transaction is a state after the transaction has been rolled back and the database has been restored to the state prior to the transaction. |
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| 248. |
The result of each intermediate operation are created and then are used for valuation of the next level operations, this evaluation is called as ________(a) Chain evaluation(b) Pipeline evaluation(c) Materialized evaluation(d) Demand driven evaluation |
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Answer» Correct choice is (c) Materialized evaluation To explain I would say: The result of each intermediate operation are created and then are used foe valuation of the next level operations, this evaluation is called as Materialized evaluation. This is not space effective as we need to construct the temporary relations which must be written to a disk. |
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| 249. |
Which of the following timestamps is used to record the time when a database has completed its write operation?(a) Start(i)(b) Validation(i)(c) Finish(i)(d) Write(i) |
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Answer» Correct option is (c) Finish(i) The explanation: There are three different timestamps for each transaction start(i), validation(i), finish(i). Finish(i) is used to record the time when a transaction has finished its write phase. |
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| 250. |
If the results of one operation are passed on to the other, it is called as ________(a) Chain(b) Pipeline(c) Materialized(d) Tree |
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Answer» The correct choice is (b) Pipeline The best I can explain: If the results of one operation are passed on to the other, it is called as Pipelined. This can be used to evaluate several expressions simultaneously. |
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