UNIT – I
PART-A
1. Define database management system?
Database management system (DBMS) is a collection of interrelated data and a set of programs to access those data.
2. List any eight applications of DBMS.
a) Banking b) Airlines c) Universities d) Credit card transactions
e) Tele communication f) Finance g) Sales h) Manufacturing
i) Human resources
3. What are the disadvantages of file processing system?
The disadvantages of file processing systems are
a) Data redundancy and inconsistency b) Difficulty in accessing data
c) Data isolation d) Integrity problems e) Atomicity problems
f) Concurrent access anomalies
4. What are the advantages of using a DBMS?
The advantages of using a DBMS are
a) Controlling redundancy b) Restricting unauthorized access
c) Providing multiple user interfaces d) Enforcing integrity constraints.
e) Providing backup and recovery
5. Mention the challenges in distributed system.
1. Heterogeneity
2. Openness
3. Security
4. Scalability
5. Failure handling
6. Concurrency
7. Transparency
6. Give the levels of data abstraction?
a) Physical level b) logical level c) view level
7. Define instance and schema?
Instance: Collection of data stored in the data base at a particular moment is called an Instance of the database.
Schema: The overall design of the data base is called the data base schema.
8. Define the terms 1) physical schema 2) logical schema.
Physical schema: The physical schema describes the database design at the physical level, which
is the lowest level of abstraction describing how the data are actually stored.
Logical schema: The logical schema describes the database design at the logical level, which describes what data are stored in the database and what relationship exists among the data.
9. What is conceptual schema?
The schemas at the view level are called sub schemas that describe different views of the database.
10. Define data model?
A data model is a collection of conceptual tools for describing data, data relationships, data
Semantics and consistency constraints.
11. What is storage manager?
A storage manager is a program module that provides the interface between the low level data stored in a database and the application programs and queries submitted to The system. Proof of sending / receiving an information E.g. digital signature
12. What are the components of storage manager?
The storage manager components include
a) Authorization and integrity manager b) Transaction manager
c) File manager d) Buffer manager
13. What is the purpose of storage manager?
The storage manager is responsible for the following
a) Interaction with he file manager
b) Translation of DML commands in to low level file system commands
c) Storing, retrieving and updating data in the database
14. List the data structures implemented by the storage manager.
The storage manager implements the following data structure
a) Data files b) Data dictionary c) indices
15. What is a data dictionary?
A data dictionary is a data structure which stores meta data about the structure of the database ie. The schema of the database.
16. What is an entity relationship model?
The entity relationship model is a collection of basic objects called entities and relationship Among those objects. An entity is a thing or object in the real world that is Distinguishable from other objects.
17. What are attributes? Give examples.
An entity is represented by a set of attributes. Attributes are descriptive properties possessed by each member of an entity set.
Example: possible attributes of customer entity are customer name, customer id, customer street, customer city.
18. What is the architectural model?
An architectural model defines the way in which the components of system interact with one another and the way in which they are mapped onto an underlying network of computers.
19. What is the fundamental model?
Fundamental models that help to reveal key problems for the designers of distributed systems. Their purpose is to specify the design issues, difficulties and threats that must be resolved in order to develop distribute systems that fulfill their tasks correctly, reliably and securely. The fundamental mode provides abstract views of just those characteristics of distributed systems that affect the dependability characteristics - correctness, reliability and security.
20. What is relationship? Give examples
A relationship is an association among several entities.
Example: A depositor relationship associates a customer with each account that he/she has.
21. Define the terms
i) Entity set ii) Relationship set
Entity set: The set of all entities of the same type is termed as an entity set.
Relationship set: The set of all relationships of the same type is termed as a relationship set.
22. Define single valued and multi valued attributes.
Single valued attributes: attributes with a single value for a particular entity are called single valued attributes.
Multi valued attributes: Attributes with a set of value for a particular entity are called multi valued attributes.
23. What are stored and derived attributes?
Stored attributes: The attributes stored in a data base are called stored attributes.
Derived attributes: The attributes that are derived from the stored attributes are called derived attributes.
24. What are composite attributes?
Composite attributes can be divided in to sub parts.
25. Define null values.
In some cases a particular entity may not have an applicable value for an attribute or if we do not know the value of an attribute for a particular entity. In these cases null value is used.
26. What is relationship? Give examples
A relationship is an association among several entities.
Example: A depositor relationship associates a customer with each account that he/she has.
27. Define the terms
i) Entity set ii) Relationship set
Entity set: The set of all entities of the same type is termed as an entity set.
Relationship set: The set of all relationships of the same type is termed as a relationship set.
28. Define single valued and multi valued attributes.
Single valued attributes: attributes with a single value for a particular entity are called single valued attributes.
Multi valued attributes: Attributes with a set of value for a particular entity are called multi valued attributes.
29. What are stored and derived attributes?
Stored attributes: The attributes stored in a data base are called stored attributes.
Derived attributes: The attributes that are derived from the stored attributes are called derived attributes.
30. What are composite attributes?
Composite attributes can be divided in to sub parts.
31. Define null values.
In some cases a particular entity may not have an applicable value for an attribute or if we do not know the value of an attribute for a particular entity. In these cases null value is used.
32. What is relationship? Give examples
A relationship is an association among several entities.
Example: A depositor relationship associates a customer with each account that he/she has.
33. Define the terms
i) Entity set ii) Relationship set
Entity set: The set of all entities of the same type is termed as an entity set.
Relationship set: The set of all relationships of the same type is termed as a relationship set.
PART-B
1. Describe a typical system architecture for DBMS
2. Explain about : Database Administrator, Database User
3. What is data independence? Why is data independence important? What are the facilities that are provided by the DBMS to achieve Physical and Logical data
Independence?
4. What are the database languages commonly used?
5. What are the different data models?
6. Outline the ANSI-SPARC 3-level DBMS architecture. Distinguish clearly between the levels
7. What are the advantages of DBMS over conventional file systems?
8. Briefly explain the 3 levels of data abstraction and the inter-relationship among these levels
9. What are the responsibilities of a database manager and a database administrator? Explain the problems that would arise if the responsibility were not met
10. “A major purpose of a database system is to provide users with an abstract view of the data." Do you agree? Why?
UNIT II
1 Write short notes on relational model
The relational model uses a collection of tables to represent both data and the relationships among those data. The relational model is an example of a record based model.
2. Define tuple and attribute
• Attributes: column headers • Tuple: Row
3. Define the term relation.
Relation is a subset of a Cartesian product of list domains.
4. Define tuple variable
Tuple variable is a variable whose domain is the set of all tuples.
5. Define the term Domain.
For each attribute there is a set of permitted values called the domain of that attribute.
6. What is a candidate key?
Minimal super keys are called candidate keys.
7. What is a primary key?
Primary key is chosen by the database designer as the principal means of identifying an entity in the entity set.
8. What is a super key?
A super key is a set of one or more attributes that collectively allows us to identify uniquely an
entity in the entity set.
9. Define- relational algebra. The relational algebra is a procedural query language. It consists
of a set of operations that take one or two relation as input and produce a new relation as output.
10. What is a SELECT operation?
The select operation selects tuples that satisfy a given predicate. We use the lowercase letter s to denote selection.
11. What is a PROJECT operation?
The project operation is a unary operation that returns its argument relation with certain attributes left out. Projection is denoted by pie (p).
12. Write short notes on domain relational calculus
The domain relational calculus uses domain variables that take on values from an attribute domain rather than values for entire tuple.
13. Define query language?
A query is a statement requesting the retrieval of information. The portion of DML that involves information retrieval is called a query language.
14. Write short notes on Schema diagram.
A database schema along with primary key and foreign key dependencies can be depicted pictorially by schema diagram. Each relation appears as a box with attributes listed inside it and the relation name above it.
15. What is foreign key?
A relation schema r1 derived from an ER schema may include among its attributes the primary key of another relation schema r2.this attribute is called a foreign key from r1 referencing r2.
16. What are the parts of SQL language?
The SQL language has several parts:
• data - definition language
• Data manipulation language
• View definition
• Transaction control
• Embedded SQL
• Integrity
• Authorization
17. What are the categories of SQL command?
SQL commands are divided in to the following categories:
1. data - definition language 2. data manipulation language
3. Data Query language 4. data control language
5. data administration statements 6. transaction control statements
18. What are the three classes of SQL expression?
SQL expression consists of three clauses:
• Select
• From
• where
19. What is the use of rename operation?
Rename operation is used to rename both relations and a attributes.
It uses the as clause, taking the form:
Old-name as new-name
20. Define tuple variable?
Tuple variables are used for comparing two tuples in the same relation. The tuple variables are defined in the from clause by way of the as clause.
21. List the string operations supported by SQL?
1) Pattern matching Operation 2) Concatenation
3) Extracting character strings 4) Converting between uppercase and lower case
Letters.
22. Give the general form of SQL query?
Select A1, A2…………., An From R1, R2……………, Rm Where P
23. List the set operations of SQL?
1) Union 2) Intersect operation 3) The except operation
24. What is the use of Union and intersection operation?
Union: The result of this operation includes all tuples that are either in r1 or in r2 or in both r1 and r2.Duplicate tuples are automatically eliminated.
Intersection: The result of this relation includes all tuples that are in both r1 and r2.
25. What are aggregate functions? And list the aggregate functions supported by SQL?
Aggregate functions are functions that take a collection of values as input and return a single value.
Aggregate functions supported by SQL are
• Average: avg
• Minimum: min
• Maximum: max
• Total: sum
• Count: count
26. What is the use of group by clause?
Group by clause is used to apply aggregate functions to a set of tuples. The attributes given in the group by clause are used to form groups. Tuples with the same value on all attributes in the group by clause are placed in one group.
27. What is the use of sub queries?
A sub query is a select-from-where expression that is nested with in another query. A common use of sub queries is to perform tests for set membership, make set comparisons, and determine set cardinality.
28. What is view in SQL? How is it defined?
Any relation that is not part of the logical model, but is made visible to a user as a virtual relation is called a view.
We define view in SQL by using the create view command. The form of the create view command is
Create view v as <query expression>
29. What is the use of with clause in SQL?
The with clause provides a way of defining a temporary view whose definition is available only to the query in which the with clause occurs.
30. List the table modification commands in SQL?
• Deletion
• Insertion
• Updates
• Update of a view
31. List out the statements associated with a database transaction?
• Commit work
• Rollback work
32. List the SQL domain Types?
SQL supports the following domain types.
1) Char(n) 2) varchar(n) 3) int 4) numeric(p,d) 5) float(n) 6) date.
33. What is the use of integrity constraints?
Integrity constraints ensure that changes made to the database by authorized users do not result
in a loss of data consistency. Thus integrity constraints guard against accidental damage to the database.
34. Mention the 2 forms of integrity constraints in ER model?
• Key declarations
• Form of a relationship
35. What is trigger?
Triggers are statements that are executed automatically by the system as the side effect of a modification to the database.
36. What are domain constraints?
A domain is a set of values that may be assigned to an attribute .all values that appear in a column of a relation must be taken from the same domain.
37. What are referential integrity constraints?
A value that appears in one relation for a given set of attributes also appears for a certain set of attributes in another relation.
38. What is assertion? Mention the forms available.
An assertion is a predicate expressing a condition that we wish the database always to satisfy.
• Domain integrity constraints.
• Referential integrity constraints
39. Give the syntax of assertion?
Create assertion <assertion name>check<predicate>
40. List the requirements needed to design a trigger.
The requirements are
• Specifying when a trigger is to be executed.
• Specify the actions to be taken when the trigger executes.
41. What is the need for triggers?
Triggers are useful mechanisms for alerting humans or for starting certain tasks automatically when certain conditions are met.
42. Give the forms of triggers?
• The triggering event can be insert or delete.
• For updated the trigger can specify columns.
• The referencing old row as clause
• The referencing new row as clause
• The triggers can be initiated before the event or after the event.
43. What does database security refer to?
Database security refers to the protection from unauthorized access and malicious destruction or alteration.
44. List some security violations (or) name any forms of malicious access.
• Unauthorized reading of data
• Unauthorized modification of data
• Unauthorized destruction of data.
45. List the types of authorization.
• Read authorization
• Write authorization
• Update authorization
• Drop authorization
46. What is authorization graph?
Passing of authorization from one user to another can be represented by an authorization graph.
47. List out various user authorization to modify the database schema.
• Index authorization
• Resource authorization
• Alteration authorization
• Drop authorization
48. What are audit trails?
An audit trail is a log of all changes to the database along with information such as which user
Performed the change and when the change was performed.
49. Mention the various levels in security measures.
• Database system
• Operating system
• Network
• Physical
• human
50. Name the various privileges in SQL?
• Delete
• Select
• Insert
• update
51. Mention the various user privileges.
• All privileges directly granted to the user or role.
• All privileges granted to roles that have been granted to the user or role.
52. Give the limitations of SQL authorization.
• The code for checking authorization becomes intermixed with the rest of the application code.
• Implementing authorization through application code rather than specifying it declaratively in SQL makes it hard to ensure the absence of loopholes.
53. Give some encryption techniques?
• DES
• AES
• Public key encryption
54. What does authentication refer?
Authentication refers to the task of verifying the identity of a person.
55. List some authentication techniques.
• Challenge response scheme.
• Digital signatures.
• Non repudiation.
PART-B
1. Explain briefly the Relational Integrity Constraints.
2. What are the various update operations on Relations?
3. Explain Relational Calculus. What are the two types of Relational Calculus?
4. Explain Relational Algebra. What are the relational algebra operations that can be performed?
5. Explain basic structure of selection statement?
6. Explain assertions, update, and view with example?
7. Explain DDL & DML commands in detail?
8. Explain join operations with its types?
9. Explain embedded SQL & Dynamic sql with example?
10. Explain in detail about security?
11. What is trigger? Explain with suitable examples?
UNIT III
1 Define Boyce codd normal form
A relation schema R is in BCNF with respect to a set F of functional dependencies if, for all
• Functional dependencies in F + of the form. _->_, where _
2 List the disadvantages of relational database system
• Repetition of data
• Inability to represent certain information.
3 What is first normal form?
The domain of attribute must include only atomic (simple, indivisible) values.
4 What are axioms?
Axioms or rules of inference provide a simpler technique for reasoning about
Functional dependencies.
5 What is meant by computing the closure of a set of functional dependency?
The closure of F denoted by F+ is the set of functional dependencies logically implied by F.
6 What is meant by normalization of data?
It is a process of analyzing the given relation schemas based on their Functional Dependencies
(FDs) and primary key to achieve the properties
• Minimizing redundancy
• Minimizing insertion, deletion and updating anomalies.
7 Define canonical cover?
A canonical cover Fc for F is a set of dependencies such that F logically implies all dependencies in FC and Fc logically implies all dependencies in F. Fc must have the following properties.
8 List the properties of canonical cover.
Fc must have the following properties.
• No functional dependency in Fc contains an extraneous attribute.
• Each left side of a functional dependency in Fc is unique.
9 Explain the desirable properties of decomposition.
• Lossless-join decomposition
• Dependency preservation
• • Repetition of information
10 12. What is 2NF?
A relation schema R is in 2NF if it is in 1NF and every non-prime attribute A in R
is fully functionally dependent on primary key.
PART-B
1 What is normalization? Explain its various forms?
2 What is functional dependency and explain F+ and alpha closure?
3 Explain the properties of decomposition with suitable examples?
UNIT IV
1 1. What is transaction?
Collections of operations that form a single logical unit of work are called transactions.
2 2. What are the two statements regarding transaction?
The two statements regarding transaction of the form:
• Begin transaction
• End transaction
3 What are the properties of transaction?
The properties of transactions are:
• Atomicity
• Consistency
• Isolation
• Durability
4 What is recovery management component?
Ensuring durability is the responsibility of a software component of the base
system called the recovery management component.
5 When is a transaction rolled back?
Any changes that the aborted transaction made to the database must be undone.
Once the changes caused by an aborted transaction have been undone, then the
transaction has been rolled back.
6 What are the states of transaction?
• The states of transaction are
• Active
• Partially committed
• Failed
• Aborted
• Committed
• Terminated
7 What is a shadow copy scheme?
It is simple, but efficient, scheme called the shadow copy schemes. It is based on making copies of the database called shadow copies that one transaction is active at a time. The scheme also assumes that the database is simply a file on disk.
8 Give the reasons for allowing concurrency?
The reasons for allowing concurrency is if the transactions run serially, a short transaction may have to wait for a preceding long transaction to complete, which can lead to unpredictable delays in running a transaction. So concurrent execution reduces the unpredictable delays in running transactions.
9 What is average response time?
The average response time is that the average time for a transaction to be completed after it has
• been submitted.
10 What are the two types of serializability?
The two types of serializability is
• Conflict serializability
• View serializability
11 Define lock?
Lock is the most common used to implement the requirement is to allow a transaction to access
1. a data item only if it is currently holding a lock on that item.
12 What are the different modes of lock?
The modes of lock are:
• Shared
• Exclusive
13 Define deadlock?
Neither of the transaction can ever proceed with its normal execution. This situation is called deadlock.
14 Define the phases of two phase locking protocol
• Growing phase: a transaction may obtain locks but not release any lock.
• Shrinking phase: a transaction may release locks but may not obtain any new locks.
15 Define upgrade and downgrade?
It provides a mechanism for conversion from shared lock to exclusive lock is known as upgrade.
It provides a mechanism for conversion from exclusive lock to shared lock is known as downgrade.
16 What is a database graph?
The partial ordering implies that the set D may now be viewed as a directed acyclic graph, called a database graph.
17 What are the two methods for dealing deadlock problem?
• The two methods for dealing deadlock problem is deadlock detection and deadlock recovery.
18 What is a recovery scheme?
An integral part of a database system is a recovery scheme that can restore the database to the consistent state that existed before the failure.
19 What are the two types of errors?
The two types of errors are:
• Logical error
• System error
20 What are the storage types?
The storage types are:
• Volatile storage
• Nonvolatile storage
21 Define blocks?
The database system resides permanently on nonvolatile storage, and is partitioned into fixed length storage units called blocks.
22 What is meant by Physical blocks?
The input and output operations are done in block units. The blocks residing on the disk are referred to as physical blocks.
23 What is meant by buffer blocks?
The blocks residing temporarily in main memory are referred to as buffer blocks.
24 What is meant by disk buffer?
The area of memory where blocks reside temporarily is called the disk buffer.
25 What is meant by log-based recovery?
The most widely used structures for recording database modifications is the log.
The log is a sequence of log records, recording all the update activities in the database. There are several types of log records.
26 What are uncommitted modifications?
The immediate-modification technique allows database modifications to be output to the database while the transaction is still in the active state. Data modifications written by active transactions are called uncommitted modifications.
27 Define shadow paging.
An alternative to log-based crash recovery technique is shadow paging. This technique needs fewer disk accesses than do the log-based methods.
28 Define page.
The database is partitioned into some number of fixed-length blocks, which are
referred to as pages.
29 Explain current page table and shadow page table.
The key idea behind the shadow paging technique is to maintain two page tables during the life of the transaction: the current page table and the shadow page table. Both the page tables are identical when the transaction starts. The current page table may be changed when a transaction performs a write operation.
30 What are the drawbacks of shadow-paging technique?
• Commit Overhead
• Data fragmentation
• Garbage collection
31 Define garbage collection.
Garbage may be created also as a side effect of crashes. Periodically, it is necessary to find all the garbage pages and to add them to the list of free pages. This process is called garbage collection.
32 Differentiate strict two phase locking protocol and rigorous two phase locking protocol.
In strict two phases locking protocol all exclusive mode locks taken by a transaction is held until that transaction commits.
Rigorous two phase locking protocol requires that all locks be held until the transaction commits.
33 How the time stamps are implemented
• Use the value of the system clock as the time stamp. That is a transaction’s time stamp is equal to the value of the clock when the transaction enters the system.
• Use a logical counter that is incremented after a new timestamp has been assigned; that is the time stamp is equal to the value of the counter.
34. What are the time stamps associated with each data item?
• W-timestamp (Q) denotes the largest time stamp if any transaction that executed WRITE (Q) successfully.
• R-timestamp (Q) denotes the largest time stamp if any transaction that executed READ (Q) successfully.
PART-B
1 How Transaction take place in DBMS?
2 Explain atomicity in Transaction with example.
3 What are schedulings in Transactions?
4 What are the anomalies with inter-leaved execution?
5 Describe the various properties and uses of serializability schedule. How is it possible to ensure serializability schedule?
6 What is Concurrency Control in DBMS?
7 What is lock management? What is locking techniques in concurrency control? What are the different types of locks? How two-phase locking is possible?
8 What are the properties of Index Locking and Predicate Locking?
9 What is timestamping in Concurrency Control?
10 What is Recovery mechanism in Database?
11 Explain in detail about shadow paging technique.
UNIT V
1 What is an index?
An index is a structure that helps to locate desired records of a relation quickly, without examining all records.
2 Define query optimization.
Query optimization refers to the process of finding the lowest –cost method of evaluating a given query.
3 What are called jukebox systems?
Jukebox systems contain a few drives and numerous disks that can be loaded into one of the drives automatically.
4 What are the types of storage devices?
• Primary storage
• Secondary storage
• Tertiary storage
• Volatile storage
• Nonvolatile storage
5 What is called remapping of bad sectors?
If the controller detects that a sector is damaged when the disk is initially formatted, or when an attempt is made to write the sector, it can logically map the sector to a different physical
Location.
6 Define access time.
Access time is the time from when a read or write request is issued to when data transfer begins.
7 Define seek time.
The time for repositioning the arm is called the seek time and it increases with the distance that the arm is called the seek time.
8 Define average seek time.
The average seek time is the average of the seek times, measured over a sequence of random requests.
9 Define rotational latency time.
The time spent waiting for the sector to be accessed to appear under the head is called the rotational latency time.
10 Define average latency time.
The average latency time of the disk is one-half the time for a full rotation of the disk.
11 What is meant by data-transfer rate?
The data-transfer rate is the rate at which data can be retrieved from or stored to the disk.
12 What is meant by mean time to failure?
The mean time to failure is the amount of time that the system could run continuously without failure.
13 What is a block and a block number?
A block is a contiguous sequence of sectors from a single track of one platter. Each request specifies the address on the disk to be referenced. That address is in the form of a block number.
14 What are called journaling file systems?
File systems that support log disks are called journaling file systems.
15 What is the use of RAID?
A variety of disk-organization techniques, collectively called redundant arrays of independent disks are used to improve the performance and reliability.
16 What is called mirroring?
The simplest approach to introducing redundancy is to duplicate every disk. This technique is called mirroring or shadowing.
17 What is called mean time to repair?
The mean time to failure is the time it takes to replace a failed disk and to restore the data on it.
18 What is called bit-level striping?
Data striping consists of splitting the bits of each byte across multiple disks. This is called bitlevel striping.
19 What is called block-level striping?
Block level striping stripes blocks across multiple disks. It treats the array of disks as a large disk, and gives blocks logical numbers.
20 What are the two main goals of parallelism?
• Load –balance multiple small accesses, so that the throughput of such accesses increases.
• Parallelize large accesses so that the response time of large accesses is reduced.
21 What are the factors to be taken into account when choosing a RAID level?
• Monetary cost of extra disk storage requirements.
• Performance requirements in terms of number of I/O operations
• Performance when a disk has failed.
• Performances during rebuild.
22 What is meant by software and hardware RAID systems?
RAID can be implemented with no change at the hardware level, using only software modification. Such RAID implementations are called software RAID systems and the systems with special hardware support are called hardware RAID systems.
23 Define hot swapping?
Hot swapping permits the removal of faulty disks and replaces it by new ones without turning power off. Hot swapping reduces the mean time to repair.
24 What are the ways in which the variable-length records arise in database systems?
• 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.
25 What is the use of a slotted-page structure and what is the information present in the
header?
The slotted-page structure is used for organizing records within a single block.
The header contains the following information.
• The number of record entries in the header.
• The end of free space
• An array whose entries contain the location and size of each record.
26 What are the two types of blocks in the fixed –length representation? Define them.
• Anchor block: Contains the first record of a chain.
• Overflow block: Contains the records other than those that are the first record of a chain.
27 What is known as heap file organization?
In the heap file organization, any record can be placed anywhere in the file where there is space for the record. There is no ordering of records. There is a single file for each relation.
28 What is known as sequential file organization?
In the sequential file organization, the records are stored in sequential order, according to the value of a “search key” of each record.
29 What is hashing file organization?
In the hashing file organization, a hash function is computed on some attribute of each record. The result of the hash function specifies in which block of the file the record should be placed.
30 What is known as clustering file organization?
In the clustering file organization, records of several different relations are stored in the same file.
31 What are the types of indices?
• Ordered indices
• Hash indices
32 What are the techniques to be evaluated for both ordered indexing and hashing?
• Access types
• Access time
• Insertion time
• Deletion time
• Space overhead
33 What are the two types of indices?
• Dense index
• Sparse index1
34 What is B-Tree?
A B-tree eliminates the redundant storage of search-key values .It allows search key values to appear only once.
35 39. What is a B+-Tree index?
A B+-Tree index takes the form of a balanced tree in which every path from the root of the root of the root of the tree to a leaf of the tree is of the same length.
36 What are the steps involved in query processing?
The basic steps are:
• Parsing and translation
• Optimization
• Evaluation
37 What is called as an N-way merge?
The merge operation is a generalization of the two-way merge used by the standard in-memory sort-merge algorithm. It merges N runs, so it is called an N-way merge.
38 What is known as fudge factor?
The number of partitions is increased by a small value called the fudge factor, which is usually 20 percent of the number of hash partitions computed.
39 What is called as recursive partitioning?
The system repeats the splitting of the input until each partition of the build input fits in the memory. Such partitioning is called recursive partitioning.
PART-B
1 Explain the implementation of fixed length & variable length records?
2 Explain sequential, clustering, heap file organization?
3 Explain Primary index, secondary index and multilevel indices?
4 Write short notes on B-tree and B+tree?
5 Explain the various algorithms used to implement selection and join operation?
6 Dense indices are faster in general, but sparse indices require less space and impose less maintenance for insertions and deletions. Why?
7 State the difference between B+trees and B trees?
8 Draw the structure of a B +tree and explain.
9 Compare and describe Indexing and Hashing
10 State the difference between dynamic and static hashing. How does these work?
11 What are the characteristics of a magnetic disk?
12 Why RAIDs are used? Why are they called so?
13 What is clustering file organisation and sequential file organisation?
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