ENGINEERING & MANAGEMENT EXAMINATIONS, DECEMBER – 2008
SEMESTER – 7
2. Explain 3-phase commit protocol. Ceri Page no 251
Why is it non-blocking ?
The new protocol allows termination for all failures during the second phase which
blocked the standard 2-phase protocol; however, we must show that blocking cannot
occur because of a failure during the third additional phase which has been added.
This is simple, because all participants are in the prepared-to-commit state when this
phase begins. Hence the termination protocol will elect a new coordinator and commit
the transaction in case of failure of the original coordinator.
The new protocol requires three phases for committing a transaction and two phases
for aborting it. Several termination protocols for operational participants and restart
protocols for failed participants can be designed to operate correctly with the 3-phasecommitment protocol.
3. Describe catalogue management in distributed database systems.
Ceri Page no: 278 i.e - CATALOG MANAGEMENT IN DISTRIBUTED DATABASE
and CONTENTS OF CATALOG
4. What is false deadlock ? How is it overcome ?
Ceri Page No: 225
5. Differentiate between distributed database and parallel database.
A parallel database system is one that seeks to improve performance through parallel
implementation of various operations such as loading data, building indexes, and
evaluating queries. Although data may be stored in a distributed fashion in such a
system, the distribution is governed solely by performance considerations.