DBMS · Transactions & Concurrency interview questions

1. A.a logical unit of work made of operations that must execute all together or not at all
2. B.the ACID property guaranteeing committed changes survive subsequent system failures
3. C.a write lock that only one transaction may hold, blocking all other access
4. D.an anomaly where re-reading the same row in a transaction yields a changed value

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1. A.Two-phase locking
2. B.Dirty read
3. C.Transaction
4. D.Exclusive lock

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1. A.Transaction — the ACID property guaranteeing a transaction is all-or-nothing, with partial work undone on failure
2. B.Transaction — a logical unit of work made of operations that must execute all together or not at all
3. C.Transaction — the ACID property guaranteeing committed changes survive subsequent system failures
4. D.Transaction — reading data written by another transaction that has not yet committed

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1. A.a logical unit of work made of operations that must execute all together or not at all
2. B.the ACID property guaranteeing a transaction is all-or-nothing, with partial work undone on failure
3. C.reading data written by another transaction that has not yet committed
4. D.an ordering of the interleaved operations of several concurrent transactions

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1. A.Dirty read
2. B.Shared lock
3. C.Transaction
4. D.Atomicity

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1. A.Atomicity — a protocol with a growing phase acquiring locks and a shrinking phase releasing them
2. B.Atomicity — a logical unit of work made of operations that must execute all together or not at all
3. C.Atomicity — the ACID property guaranteeing a transaction is all-or-nothing, with partial work undone on failure
4. D.Atomicity — a write lock that only one transaction may hold, blocking all other access

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1. A.an ordering of the interleaved operations of several concurrent transactions
2. B.the ACID property guaranteeing committed changes survive subsequent system failures
3. C.the ACID property ensuring a transaction takes the database from one valid state to another
4. D.the ACID property guaranteeing a transaction is all-or-nothing, with partial work undone on failure

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1. A.Consistency
2. B.Atomicity
3. C.Conflict serializability
4. D.Shared lock

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1. A.Consistency — the ACID property ensuring a transaction takes the database from one valid state to another
2. B.Consistency — the ACID property guaranteeing committed changes survive subsequent system failures
3. C.Consistency — an ordering of the interleaved operations of several concurrent transactions
4. D.Consistency — the ACID property guaranteeing a transaction is all-or-nothing, with partial work undone on failure

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1. A.reading data written by another transaction that has not yet committed
2. B.the ACID property ensuring concurrent transactions do not interfere with each other's results
3. C.a write lock that only one transaction may hold, blocking all other access
4. D.a logical unit of work made of operations that must execute all together or not at all

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1. A.View serializability
2. B.Isolation
3. C.Conflict serializability
4. D.Consistency

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1. A.Isolation — a schedule property equivalent to some serial order by swapping non-conflicting operations
2. B.Isolation — the ACID property ensuring concurrent transactions do not interfere with each other's results
3. C.Isolation — reading data written by another transaction that has not yet committed
4. D.Isolation — the ACID property guaranteeing committed changes survive subsequent system failures

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1. A.a schedule property equivalent to some serial order by swapping non-conflicting operations
2. B.the ACID property ensuring concurrent transactions do not interfere with each other's results
3. C.the ACID property guaranteeing committed changes survive subsequent system failures
4. D.a weaker serializability where a schedule yields the same reads and final writes as a serial one

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1. A.Shared lock
2. B.Durability
3. C.Two-phase locking
4. D.Consistency

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1. A.Durability — an anomaly where re-reading the same row in a transaction yields a changed value
2. B.Durability — the ACID property guaranteeing committed changes survive subsequent system failures
3. C.Durability — an anomaly where one transaction's write overwrites another's uncommitted concurrent update
4. D.Durability — the ACID property ensuring concurrent transactions do not interfere with each other's results

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1. A.an anomaly where re-running a query returns new rows inserted by another transaction
2. B.a write lock that only one transaction may hold, blocking all other access
3. C.the ACID property guaranteeing a transaction is all-or-nothing, with partial work undone on failure
4. D.an ordering of the interleaved operations of several concurrent transactions

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1. A.Schedule
2. B.Dirty read
3. C.Lost update
4. D.Consistency

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1. A.Schedule — an ordering of the interleaved operations of several concurrent transactions
2. B.Schedule — a protocol with a growing phase acquiring locks and a shrinking phase releasing them
3. C.Schedule — a write lock that only one transaction may hold, blocking all other access
4. D.Schedule — reading data written by another transaction that has not yet committed

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1. A.a protocol with a growing phase acquiring locks and a shrinking phase releasing them
2. B.reading data written by another transaction that has not yet committed
3. C.a schedule property equivalent to some serial order by swapping non-conflicting operations
4. D.a read lock that several transactions may hold on the same item simultaneously

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1. A.Exclusive lock
2. B.Phantom read
3. C.Two-phase locking
4. D.Conflict serializability

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1. A.Conflict serializability — a schedule property equivalent to some serial order by swapping non-conflicting operations
2. B.Conflict serializability — a protocol with a growing phase acquiring locks and a shrinking phase releasing them
3. C.Conflict serializability — a read lock that several transactions may hold on the same item simultaneously
4. D.Conflict serializability — a write lock that only one transaction may hold, blocking all other access

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1. A.the ACID property ensuring concurrent transactions do not interfere with each other's results
2. B.a weaker serializability where a schedule yields the same reads and final writes as a serial one
3. C.a schedule property equivalent to some serial order by swapping non-conflicting operations
4. D.an ordering of the interleaved operations of several concurrent transactions

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1. A.View serializability
2. B.Schedule
3. C.Unrepeatable read
4. D.Consistency

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1. A.View serializability — a weaker serializability where a schedule yields the same reads and final writes as a serial one
2. B.View serializability — reading data written by another transaction that has not yet committed
3. C.View serializability — a schedule property equivalent to some serial order by swapping non-conflicting operations
4. D.View serializability — an anomaly where one transaction's write overwrites another's uncommitted concurrent update

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1. A.the ACID property ensuring a transaction takes the database from one valid state to another
2. B.a protocol with a growing phase acquiring locks and a shrinking phase releasing them
3. C.a read lock that several transactions may hold on the same item simultaneously
4. D.an anomaly where one transaction's write overwrites another's uncommitted concurrent update

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1. A.Two-phase locking
2. B.Conflict serializability
3. C.Shared lock
4. D.Unrepeatable read

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1. A.Two-phase locking — a protocol with a growing phase acquiring locks and a shrinking phase releasing them
2. B.Two-phase locking — a schedule property equivalent to some serial order by swapping non-conflicting operations
3. C.Two-phase locking — reading data written by another transaction that has not yet committed
4. D.Two-phase locking — an anomaly where re-running a query returns new rows inserted by another transaction

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1. A.reading data written by another transaction that has not yet committed
2. B.a read lock that several transactions may hold on the same item simultaneously
3. C.a write lock that only one transaction may hold, blocking all other access
4. D.the ACID property ensuring concurrent transactions do not interfere with each other's results

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1. A.Lost update
2. B.Exclusive lock
3. C.Isolation
4. D.Shared lock

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1. A.Shared lock — the ACID property ensuring concurrent transactions do not interfere with each other's results
2. B.Shared lock — a schedule property equivalent to some serial order by swapping non-conflicting operations
3. C.Shared lock — a logical unit of work made of operations that must execute all together or not at all
4. D.Shared lock — a read lock that several transactions may hold on the same item simultaneously

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