1. What is distributed database?Explain with a neat diagram.
2. Define referential Integrity Constraintsand give an example
3. What are the main advantagesand disadvantagesof distributed databases?
4. Differentiate betweenparallel and distributed databases.
5. 3. Compareand contrast LAN, MAN and WAN.
6. What are the desiredproperties of distributed databases?
7. What are homogeneousand heterogeneousDDBMSs? Explain with an example.
8. 5. Differentiatebetweenloosely coupledsystemsand tightly coupledsystems.
9. What do you mean by datareplication? What are its advantagesand disadvantages?
10. What do you mean by fragmentedschemas?What are the effects of replication on fragmentation?
l. What is a fragmentof a relation?What are the main typesof datafragments?Why is fragmentation
an usefulconceptin distributeddatabasedesign?What is horizontal datafragmentation,vertical data
fragmentation
& mixed datafragmentation?
Explainwith an example.
2. Considerthefollowingrelations:
EMP (EMPNUM,NAME, SAL, TAX, MGRNUM, DEPTNUM)
Fragments
horizontalEMPl, EMP2,EMP3basedon DEpTNUM
DEPT(DEPTNUM,NAME, AREA, MGRNUM)
Fragments
horizontalDEPTl, DEPT2,DEPT3basedon DEpTNUM
SUPPLIER(SNUM,NAME, CITY)
SUPPLY(SNUM, PNUM, DEPTNUM,QUAN)
Fragmentshorizontal SUPPLIERI, SUPPLIER2basedon CITY. Fragmentsderivedhorizontal
SUPPLY1,SUPPLY2basedon SNUM corresponding
fragments
of SUPPLIERrelation.
3. Contrast between .Distributed database and parallel database,Homogeneousdatabase and
heterogeneous
database
& Horizontalfragmentationandverticalfragmentation.
4. Commentson the following statements:
a) "Derived horizontal fragmentation might lead to violation of disjointnesscondition in between
fragments".
b) !'Horizontal fragments are necessarilydisjoint".
c) "Redundancy control is not at all an objective for designing distributed databasesystem,since
the samefragment may reside in multiple sites".
5. Give an example of an IT company, accessinga databasethat is distributed over the regions of the
country, in which the relevant predicates for data distribution are not in the text of the application
program.