Transactions and Concurrency Control
Transactions and Concurrency Control
Questions
Which of the following scenarios may leaves the transaction vulnerable to dirty reads, phantom reads etc.. in a database system?
- A transaction writes a data item after it is read by an uncommitted transaction.
- A transaction reads a data item after it is read by an uncommitted transaction.
- A transaction reads a data item after it is written by a committed transaction.
- A transaction reads a data item after it is written by an uncommitted transaction.
Which one is not a property of a transaction?
- Atomicity
- Isolation
- Durability
- Exchanging
In Oracle, commit and savepoint commands come under
- Data Definition Language
- Data Manipulation Language
- Transaction Control Language
- Object Oriented Language
- Procedure Oriented Language
In which of the following conditions is a transaction said to be in a committed state?
- After the successful execution of the transaction
- After the discovery that normal execution can no longer proceed
- When it is in its initial state
- After the final statement has been executed
- After the transaction has been rolled back
Which of the following calls is made in Oracle to perform work at some remote database?
- Rollback
- Commit
- Remote procedure calls
- System change number
- Savepoint
_________ are Transaction Control Language commands in SQL.
- Grant and Commit
- Savepoint and Revoke
- Grant and Revoke
- Commit and Rollback
Which of the following phases in commit mechanism is the one in which the coordinator asks all other nodes to commit the transaction?
- Prepare phase
- Forget phase
- Commit phase
- Global coordinator
- Client
When a transaction is executing, it is said to be in _____ state.
- active
- partially committed
- failed
- committed
- abort
Transaction X holds a shared lock R. What happens if transaction Y requests for a shared lock on R?
- Results in deadlock situation
- Immediately granted
- Immediately rejected
- Granted as is released by X
The point of synchronization between a database and transaction log file is known as
- checkpoint
- backup mechanism
- shadow paging
- cascading rollback
- recovery
A transaction is said to be in which state, when it can no longer proceed?
- Active
- Failed
- Partially committed
- Aborted
- Committed
A transaction is said to be in which state, when it is rolled back?
- Aborted
- Active
- Partially committed
- Failed
- Committed
_______ command is used to undo the work done in the current transaction.
- Revoke
- Rollback
- Savepoint
- Commit
Which of the following is the first step in the 'transaction processing cycle', which captures business data through various modes such as optical scanning or at an electronic commerce website?
- Document and report generation
- Database maintenance
- Transaction processing
- Data entry
Which of the following transactions in distributed databases guarantees that all statements in a transaction either commit or rollback as a unit?
- Remote transaction
- Distributed transaction
- Two-phase commit mechanism
- Global database name
- None of these