Q.1
A semijoin is which of the following?
  • Only the joining attributes are sent from one site to another and then all of the rows are returned.
  • All of the attributes are sent from one site to another and then only the required rows are returned.
  • Only the joining attributes are sent from one site to another and then only the required rows are returned.
  • All of the attributes are sent from one site to another and then only the required rows are returned.
Q.2
Storing a separate copy of the database at multiple locations is which of the following?
  • Data Replication
  • Horizontal Partitioning
  • Vertical Partitioning
  • Horizontal and Vertical Partitioning
Q.3
Replication should be used when which of the following exist?
  • When transmission speeds and capacity in a network prohibit frequent refreshing of large tables.
  • When using many nodes with different operating systems and DBMSs and database designs.
  • The application's data can be somewhat out-of-date.
  • All of the above.
Q.4
A homogenous distributed database is which of the following?
  • The same DBMS is used at each location and data are not distributed across all nodes.
  • The same DBMS is used at each location and data are distributed across all nodes.
  • A different DBMS is used at each location and data are not distributed across all nodes.
  • A different DBMS is used at each location and data are distributed across all nodes.
Q.5
Which of the following is true concerning a global transaction?
  • The required data are at one local site and the distributed DBMS routes requests as necessary.
  • The required data are located in at least one nonlocal site and the distributed DBMS routes requests as necessary.
  • The required data are at one local site and the distributed DBMS passes the request to only the local DBMS.
  • The required data are located in at least one nonlocal site and the distributed DBMS passes the request to only the local DBMS.
Q.6
Some of the columns of a relation are at different sites is which of the following?
  • Data Replication
  • Horizontal Partitioning
  • Vertical Partitioning
  • Horizontal and Vertical Partitioning
Q.7
Location transparency allows for which of the following?
  • Users to treat the data as if it is at one location
  • Programmers to treat the data as if it is at one location
  • Managers to treat the data as if it is at one location
  • All of the above
Q.8
A transaction manager is which of the following?
  • Maintains a log of transactions
  • Maintains before and after database images
  • Maintains appropriate concurrency control
  • All of the above
Q.9
An autonomous homogenous environment is which of the following?
  • The same DBMS is at each node and each DBMS works independently.
  • The same DBMS is at each node and a central DBMS coordinates database access.
  • A different DBMS is at each node and each DBMS works independently.
  • A different DBMS is at each node and a central DBMS coordinates database access.
Q.10
A distributed database has which of the following advantages over a centralized database?
  • Software cost
  • Software complexity
  • Slow Response
  • Modular growth
Q.11
Single coordinator approach has the following advantages :
  • Simple implementation
  • Simple deadlock handling
  • bottleneck
  • All of the mentioned
Q.12
What things are transaction coordinator is responsible for ?
  • Starting the execution of the transaction
  • Breaking transaction into a number of subtransactions
  • Coordinating the termination of the transaction
  • All of the mentioned
Q.13
What are the advantages of token(with rings) passing approach ?i) One processor as coordinator which handles all requestsii) No starvation if the ring is unidirectionaliii) There are many messages passed per section entered if few users want to get in sectioniv) One processor as coordinator which handles all requestsv) Only one message/entry if everyone wants to get in
  • i
  • ii and iii
  • i, ii and iii
  • i, ii and iv
Q.14
What are the characteristics of tightly coupled system ?i) Different clockii) Use communication linksiii) Same clockiv) Distributed systems
  • i
  • i and iv
  • i, ii and iii
  • ii, iii and iv
Q.15
In distributed systems, transaction coordinator
  • starts the execution of transaction
  • breaks the transaction into number of sub transactions
  • coordinates the termination of the transaction
  • all of the mentioned
Q.16
What are non characteristics of session semantics ?
  • Each client obtains a working copy from the server
  • When file is closed, the modified file is copied to the file server
  • The burden of coordinating file sharing is ignored by the system
  • Easy to implement in a single processor system
Q.17
What is coherency of replicated data ?
  • All replicas are identical at all times
  • Replicas are perceived as identical only at some points in time
  • Users always read the most recent data in the replicas
  • All of the mentioned
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