Persistence interview questions

15 real Persistence questions from the Redis bank, as asked in Indian campus drives and tech interviews. Every question has a verified answer and an AI-tutor explanation on placd — free to start.

1. What is RDB snapshot?

Junior
  1. A.the tunable controlling how often buffered writes are flushed to disk, with everysec offering a balance of safety and throughput
  2. B.a durability mode that logs every write command as it happens so the dataset can be reconstructed by replaying the log on restart
  3. C.a point-in-time binary dump of the whole dataset written to disk at intervals, compact and fast to load but able to lose recent writes
  4. D.a background compaction that rebuilds the write log into the smallest set of commands needed to recreate the current state
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2. Which term means: "a point-in-time binary dump of the whole dataset written to disk at intervals, compact and fast to load but able to lose recent writes"?

Junior
  1. A.Hybrid persistence
  2. B.Append-only file
  3. C.fsync policy
  4. D.RDB snapshot
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3. Which statement is correct?

Junior
  1. A.RDB snapshot — a background compaction that rebuilds the write log into the smallest set of commands needed to recreate the current state
  2. B.RDB snapshot — a point-in-time binary dump of the whole dataset written to disk at intervals, compact and fast to load but able to lose recent writes
  3. C.RDB snapshot — the tunable controlling how often buffered writes are flushed to disk, with everysec offering a balance of safety and throughput
  4. D.RDB snapshot — a durability mode that logs every write command as it happens so the dataset can be reconstructed by replaying the log on restart
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4. What is Append-only file?

Mid
  1. A.a point-in-time binary dump of the whole dataset written to disk at intervals, compact and fast to load but able to lose recent writes
  2. B.a durability mode that logs every write command as it happens so the dataset can be reconstructed by replaying the log on restart
  3. C.a format combining a compact base snapshot with a tail of recent commands, giving fast reloads plus minimal data loss
  4. D.the tunable controlling how often buffered writes are flushed to disk, with everysec offering a balance of safety and throughput
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5. Which term means: "a durability mode that logs every write command as it happens so the dataset can be reconstructed by replaying the log on restart"?

Mid
  1. A.Log rewrite
  2. B.Append-only file
  3. C.RDB snapshot
  4. D.Hybrid persistence
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6. Which statement is correct?

Mid
  1. A.Append-only file — the tunable controlling how often buffered writes are flushed to disk, with everysec offering a balance of safety and throughput
  2. B.Append-only file — a durability mode that logs every write command as it happens so the dataset can be reconstructed by replaying the log on restart
  3. C.Append-only file — a format combining a compact base snapshot with a tail of recent commands, giving fast reloads plus minimal data loss
  4. D.Append-only file — a background compaction that rebuilds the write log into the smallest set of commands needed to recreate the current state
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7. What is fsync policy?

Mid
  1. A.the tunable controlling how often buffered writes are flushed to disk, with everysec offering a balance of safety and throughput
  2. B.a format combining a compact base snapshot with a tail of recent commands, giving fast reloads plus minimal data loss
  3. C.a background compaction that rebuilds the write log into the smallest set of commands needed to recreate the current state
  4. D.a point-in-time binary dump of the whole dataset written to disk at intervals, compact and fast to load but able to lose recent writes
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8. Which term means: "the tunable controlling how often buffered writes are flushed to disk, with everysec offering a balance of safety and throughput"?

Mid
  1. A.fsync policy
  2. B.Hybrid persistence
  3. C.RDB snapshot
  4. D.Log rewrite
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9. Which statement is correct?

Mid
  1. A.fsync policy — a format combining a compact base snapshot with a tail of recent commands, giving fast reloads plus minimal data loss
  2. B.fsync policy — the tunable controlling how often buffered writes are flushed to disk, with everysec offering a balance of safety and throughput
  3. C.fsync policy — a durability mode that logs every write command as it happens so the dataset can be reconstructed by replaying the log on restart
  4. D.fsync policy — a point-in-time binary dump of the whole dataset written to disk at intervals, compact and fast to load but able to lose recent writes
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10. What is Hybrid persistence?

Senior
  1. A.a durability mode that logs every write command as it happens so the dataset can be reconstructed by replaying the log on restart
  2. B.the tunable controlling how often buffered writes are flushed to disk, with everysec offering a balance of safety and throughput
  3. C.a point-in-time binary dump of the whole dataset written to disk at intervals, compact and fast to load but able to lose recent writes
  4. D.a format combining a compact base snapshot with a tail of recent commands, giving fast reloads plus minimal data loss
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11. Which term means: "a format combining a compact base snapshot with a tail of recent commands, giving fast reloads plus minimal data loss"?

Senior
  1. A.RDB snapshot
  2. B.fsync policy
  3. C.Hybrid persistence
  4. D.Append-only file
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12. Which statement is correct?

Senior
  1. A.Hybrid persistence — a background compaction that rebuilds the write log into the smallest set of commands needed to recreate the current state
  2. B.Hybrid persistence — a point-in-time binary dump of the whole dataset written to disk at intervals, compact and fast to load but able to lose recent writes
  3. C.Hybrid persistence — a format combining a compact base snapshot with a tail of recent commands, giving fast reloads plus minimal data loss
  4. D.Hybrid persistence — a durability mode that logs every write command as it happens so the dataset can be reconstructed by replaying the log on restart
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13. What is Log rewrite?

Senior
  1. A.a background compaction that rebuilds the write log into the smallest set of commands needed to recreate the current state
  2. B.a durability mode that logs every write command as it happens so the dataset can be reconstructed by replaying the log on restart
  3. C.a point-in-time binary dump of the whole dataset written to disk at intervals, compact and fast to load but able to lose recent writes
  4. D.the tunable controlling how often buffered writes are flushed to disk, with everysec offering a balance of safety and throughput
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14. Which term means: "a background compaction that rebuilds the write log into the smallest set of commands needed to recreate the current state"?

Senior
  1. A.Hybrid persistence
  2. B.Log rewrite
  3. C.Append-only file
  4. D.fsync policy
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15. Which statement is correct?

Senior
  1. A.Log rewrite — a point-in-time binary dump of the whole dataset written to disk at intervals, compact and fast to load but able to lose recent writes
  2. B.Log rewrite — a durability mode that logs every write command as it happens so the dataset can be reconstructed by replaying the log on restart
  3. C.Log rewrite — a background compaction that rebuilds the write log into the smallest set of commands needed to recreate the current state
  4. D.Log rewrite — the tunable controlling how often buffered writes are flushed to disk, with everysec offering a balance of safety and throughput
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