DBMS-Distributed Database Systems
DBMS-Distributed Database Systems
21. Data replication decreases the availability of data to read-only transactions.
- TRUE
- FALSE
22. In distributed systems, each site generates unique local timestamp using either a logical counter or the local clock and concatenates it with the site identifier.
- TRUE
- FALSE
23. In disributted locking, the DDBS maintains a lock manager at each site whose function is to administer the lock and unlock requests for those data items that are stored at that site.
- TRUE
- FALSE
24. In distributed systems, each site generates unique local tmestamp using either a logical counter or the local clock and concatenates it with the site identifier.
- TRUE
- FALSE
26. The two-phase commit protocol guarantees that all database servers participating in a distributed transaction either all commit or all abort.
- TRUE
- FALSE
28. A distributed database system allows applications to access data from
- local database
- remote database
- both local and remote database
- None of these
29. In homogeneous DDBS,
- there are several sites, each running their own applications on the same DBMS software.
- all sites have identical DBMS software
- all users (or clients) use identical software
- All of these
30. In heterogeneous DDBS
- different sites run under the control of different DBMSs, essentially autonomously.
- different sites are connected somehow to enable access to data from multiple sites.
- different sites may use different schemas, and different DBMS software.
- All of these.