Showing posts with label GTU MCA 2ND SEMESTER. Show all posts
Showing posts with label GTU MCA 2ND SEMESTER. Show all posts
Tuesday, 9 August 2011
Friday, 26 November 2010
DBMS - II ASSIGNMENT | Assignment Database Backup and Recovery
23:13
vishal pandya
M.C.A. Semester - II
620006 – Databse Management System - II
Assignment – 3 (Database Backup and Recovery)
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Q-1. Explain the Following Questions in detail.
1). What is Database Backup? Why backup is needed? Explain Types of Database Backup?
2). Discuss different types of database failures that may occur in database environment?
3). What is Recovery? Explain types of Recovery? (Forward and Backward Recovery)
4). What is Log Based Recovery? Explain all Log based Recovery technique with Example?
5). What is Checkpoint? How is checkpoint information is used in recovery operation following System crash explain with example?
6). Describe Shadow Paging Recovery Technique? Under what circumstances does it
not require a transaction log? List advantages and disadvantage of shadow paging?
not require a transaction log? List advantages and disadvantage of shadow paging?
7). What is Database Buffer? Explain Buffer Management technique used in database recovery?
8). Table : Transaction T1
Time shot | Transaction Step | Actions |
Time-1 | Read (A,a1) | Read current employee’s load balance. |
Time-2 | a1:= a1 – 500 | Debit the Account by INR 500 |
Time-3 | Write(A,a1) | Write the new loan balance |
Time-4 | Read (B,b1) | Read the current account payable balance |
Time-5 | b1 := b1 + 500 | Credit the account balance by INR 500 |
Time-6 | Write(B,b1) | Write the new balance |
Time-7 | Commit T1 | Commit entire transaction |
Consider the transaction as above Table to create log entries for immediate updates. Suppose, that a failure occurs just after the transaction log record for action Write(B,b1) has been Written.
a). Show the Contents of transaction log at the time of failure.
b). What action is necessary and Why?
c). What are the Resulting value of A and B?
9). Consider the transaction as above Table to create log entries for deferred updates. Suppose, that a failure occurs just after the record is written to the transaction log?
a). Show the Contents of transaction log at the time of failure.
b). What action is necessary and Why?
c). What are the Resulting value of A and B?
10). Consider the following Transaction Step for Immediate Update Technique.
Initial Value of A=1000, B=2000 and C=700.
Initial Value of A=1000, B=2000 and C=700.
Transaction Step | Actions |
Begin Transaction T1 | Start Transaction T1 |
Read (A) | Read Value A |
A:= A – 50 | Deduct 50 from A |
Write(A) | Write the new value of A |
Read (B) | Read the Value of B |
B := B + 50 | Add 50 to B |
Write(B) | Write the new value of B |
End Transaction | Commit entire transaction T1 |
Begin Transaction T2 | Start Transaction T2 |
Read (C) | Read Value of C |
C:=C-100 | Deduct 100 from C |
Write (C) | Write the new value for C |
End Transaction T2 | Commit Entrire transaction T2 |
- Create Log entries for Above transaction steps.
- Let us Assume that the crash occurs just after the log record for step write(B) of transaction T1 then
- What action is necessary and why?
- What are the resulting value of A and B
- Let us Assume that Crash comes just after the log record for the Wrtite(C) of Transaction T2 then
- Finally, Let us Assume that Crash occurs just after the log record for Transaction T2,Commit
- What action is necessary and Why?
- What are the resulting value of A and B?
11). Consider the following log entries.
Log Entries |
T1,Start |
T1,A,5000,4500 |
T1,Commit |
Checkpoint |
T2,Start |
T2,B,1000,1050 |
T2,C,4000,3900 |
T2,Commit |
T3,Start |
T3,D,2500,2000 |
T4,Start |
T4,E,1000,1200 |
T4,F,1200,1400 |
Suppose, that system crash is occurs after the last write entry of F of transaction T4
then What action is necessary and why?
then What action is necessary and why?
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Q-2. Differentiate the following :
1). Deferred Update Vs Immediate Update
2). Rollforward Vs Rollback
3). Stable Storage Vs Disk
4). Volatile Storage Vs Non-Volatile Storage
5). System Crash Vs Media Failure
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Q-3. Answer the following in One line?
1) If the buffer pool is large enough that uncommited data are never forced to disk, is UNDO still necessary?
2) How about REDO?
3) If updates are always forced to disk when a transaction is performed, is UNDO still necessary?
4) How about REDO?
5) After a soft crash, where in the log should Analysis start?
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Assignment | Database Security | database management system - II
22:55
vishal pandya
M.C.A. Semester - II
620006 – Databse Management System - II
Assignment – 4 (Database Security)
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Q-1. Explain the Following Questions in detail.
1).What is Security? Explain the importance.
2).What is database security? Explain the purpose and scope of database security.
3).Explain the different threats of database security.
4).List the types of database security issues.
5).What is Access control? Define the types of access control.
6).Explain Discretionary Access Control.
7).Describe the Granting privileges using SQL with syntax and example.
8).Describe the Revoking privileges using SQL with syntax and example.
9).Explain the concept of Audit Trail?
10).Explain the Mandatory Access Control.
11).What is statistics database security?
12).What do you mean by firewall? What are firewall techniques that are used in database Security?
13).Explain data Encryption with different schemes.
14).What is meant by privileges? Discuss the types of privileges at account or system level and Table or relational level?
15).Using Polyalphabetic substitution method and encryption key, “SECURITY”, encrypt the plaintext message “SELL ALL STOCKS”
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Q-2. Differentiate the following :
1).Security Vs integrity
2).Discretionary Access Control Vs Mandatory Access Control
3).Authorization Vs Authentication.
4).Simple Property Vs Star Property
5).Audit Trail Vs Transaction Log
6).Simple Substitution Method Vs Polyalphabetic Substitution Method
Databse Management System - II | Assignment - 5 Relational Algebra
12:14
vishal pandya
M.C.A. Semester - II
620006 – Databse Management System - II
Assignment – 5 (Relational Algebra)
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Q-1. Explain the Following Questions in detail.
1). What is relational Algebra?
2). Explain SELECTION operator with Example?
3). Explain PROJECTION operator with Example?
4). Explain UNION operator with Example?
5). Explain SET DIFFERENCE operator with Example?
6). Explain CARTESIAN PRODUCT operator with Example?
7). Explain RENAME operator with Example?
8). Explain SET INTERSECTION operator with Example?
9). Explain NATURAL JOIN operator with Example?
10). Explain DIVISION operator with Example?
11). Explain ASSIGNMENT operator with Example?
12). Explain INSERT, DELETE and UPDATE operator with Example?
Q-2. Query Examples in Relational Algebra and SQL
Consider the relation schemas as follows and Convert Following query into SQL and Relational Algebra.
WORKS (PERSON_NAME, COMPANY_NAME, SALARY)
LIVES (PERSON_NAME, STREET, CITY)
LOCATED_IN (COMPANY_NAME, CITY)
MANAGERS (PERSON_NAME, MANAGER_NAME)
Where manager_name referes to Person_name
A) Find the name of the persons who work for company ‘FBC’
B) List the names of the persons who work for company ’FBC’ along with the cities they live in.
C) Find the persons who work for company ’FBC’ with a salary of more than 10000. List the names of these persons along with the streets and cities where they live.
D) Find the names of the persons who live and work in the same city.
E) Find the names of the persons who live in the same city and on the same street as their managers.
F) Find the names of the persons who do not work for company ’FBC’.
G) Find the persons whose salaries are more than the salary of everybody who work for company ’SBC’.
H) Find the names of the companies that is located in every city where company ’SBC’ is located in.
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