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level: Client server databases

Questions and Answers List

level questions: Client server databases

QuestionAnswer
What does commitment ordering attempt to doAttempt to minimise issues from occurring with the database
How does Serialisation stop concurrent accessrequests from other users are placed in a queue. Once the first user has finished using the field, the next command in the queue is executed and so on
What does commitment ordering take into accountThe impact of commands on other parts of the database
How does Timestamp ordering stop concurrent accessEach commands assigned a timestamp Commands are carried out on the field in the order of their timestamps.
How do record locks stop concurrent accessWhen a record is accessed by one user, it is immediately locked to other users until the first user has finished using it. Other users are blocked from accessing or modifying the content of a field until it has been unlocked
State wen the concurrent access issue occursWhen different users attempt to access the same field at the same time
How can the concurrent access issue be manageduse of record locks, serialisation, timestamp ordering, commitment ordering
How does commitment ordering stop concurrent accessAn algorithm is used to work out an optimum order in which to execute commands for the same field
What can concurrent access issue result in?can result in database updates being lost
Describe what the 'concurrent access issue' is with relation to client server databasesWhen different users attempt to access the same field at the same time
What does a client server database provide access to?Database
Who does a client server database provide access toMultiple clients
What do commands act onFields in databases