Join Algorithms interview questions

18 Join Algorithms questions from the SQL bank, written for Indian campus drives and tech interviews. Every question has a verified answer and an AI-tutor explanation on placd.

Free to start: the 2-minute IT readiness check — six questions and a result.

Take the free IT readiness check

or take a mock interview set up for this area

1. What is Nested loop join?

Mid
  1. A.an algorithm that scans the outer input and, for each row, probes the inner input, ideal when one side is small or indexed
  2. B.a distributed strategy that copies a small table to every node so each can join its local partition without reshuffling
  3. C.an algorithm that builds an in-memory hash table on one input and probes it with the other, favored for large unsorted equality joins
  4. D.the sequence in which the optimizer combines tables, chosen to keep intermediate result sizes as small as possible

Answer + AI explanation with Pro

2. Which term means: "an algorithm that scans the outer input and, for each row, probes the inner input, ideal when one side is small or indexed"?

Mid
  1. A.Hash join
  2. B.Broadcast join
  3. C.Nested loop join
  4. D.Merge join

Answer + AI explanation with Pro

3. Which statement is correct?

Mid
  1. A.Nested loop join — an algorithm that consumes two inputs already sorted on the key and advances through them in lockstep to match rows
  2. B.Nested loop join — an algorithm that scans the outer input and, for each row, probes the inner input, ideal when one side is small or indexed
  3. C.Nested loop join — a distributed strategy that repartitions both inputs on the join key across nodes so matching rows land together
  4. D.Nested loop join — the sequence in which the optimizer combines tables, chosen to keep intermediate result sizes as small as possible

Answer + AI explanation with Pro

4. What is Hash join?

Mid
  1. A.an algorithm that consumes two inputs already sorted on the key and advances through them in lockstep to match rows
  2. B.the sequence in which the optimizer combines tables, chosen to keep intermediate result sizes as small as possible
  3. C.an algorithm that builds an in-memory hash table on one input and probes it with the other, favored for large unsorted equality joins
  4. D.a distributed strategy that repartitions both inputs on the join key across nodes so matching rows land together

Answer + AI explanation with Pro

5. Which term means: "an algorithm that builds an in-memory hash table on one input and probes it with the other, favored for large unsorted equality joins"?

Mid
  1. A.Nested loop join
  2. B.Partitioned join
  3. C.Hash join
  4. D.Merge join

Answer + AI explanation with Pro

6. Which statement is correct?

Mid
  1. A.Hash join — the sequence in which the optimizer combines tables, chosen to keep intermediate result sizes as small as possible
  2. B.Hash join — an algorithm that scans the outer input and, for each row, probes the inner input, ideal when one side is small or indexed
  3. C.Hash join — an algorithm that consumes two inputs already sorted on the key and advances through them in lockstep to match rows
  4. D.Hash join — an algorithm that builds an in-memory hash table on one input and probes it with the other, favored for large unsorted equality joins

Answer + AI explanation with Pro

7. What is Merge join?

Mid
  1. A.an algorithm that consumes two inputs already sorted on the key and advances through them in lockstep to match rows
  2. B.a distributed strategy that copies a small table to every node so each can join its local partition without reshuffling
  3. C.the sequence in which the optimizer combines tables, chosen to keep intermediate result sizes as small as possible
  4. D.an algorithm that builds an in-memory hash table on one input and probes it with the other, favored for large unsorted equality joins

Answer + AI explanation with Pro

8. Which term means: "an algorithm that consumes two inputs already sorted on the key and advances through them in lockstep to match rows"?

Mid
  1. A.Merge join
  2. B.Nested loop join
  3. C.Partitioned join
  4. D.Broadcast join

Answer + AI explanation with Pro

9. Which statement is correct?

Mid
  1. A.Merge join — an algorithm that builds an in-memory hash table on one input and probes it with the other, favored for large unsorted equality joins
  2. B.Merge join — an algorithm that scans the outer input and, for each row, probes the inner input, ideal when one side is small or indexed
  3. C.Merge join — a distributed strategy that repartitions both inputs on the join key across nodes so matching rows land together
  4. D.Merge join — an algorithm that consumes two inputs already sorted on the key and advances through them in lockstep to match rows

Answer + AI explanation with Pro

10. What is Join order?

Senior
  1. A.an algorithm that builds an in-memory hash table on one input and probes it with the other, favored for large unsorted equality joins
  2. B.the sequence in which the optimizer combines tables, chosen to keep intermediate result sizes as small as possible
  3. C.an algorithm that consumes two inputs already sorted on the key and advances through them in lockstep to match rows
  4. D.a distributed strategy that copies a small table to every node so each can join its local partition without reshuffling

Answer + AI explanation with Pro

11. Which term means: "the sequence in which the optimizer combines tables, chosen to keep intermediate result sizes as small as possible"?

Senior
  1. A.Broadcast join
  2. B.Join order
  3. C.Nested loop join
  4. D.Merge join

Answer + AI explanation with Pro

12. Which statement is correct?

Senior
  1. A.Join order — a distributed strategy that copies a small table to every node so each can join its local partition without reshuffling
  2. B.Join order — an algorithm that consumes two inputs already sorted on the key and advances through them in lockstep to match rows
  3. C.Join order — the sequence in which the optimizer combines tables, chosen to keep intermediate result sizes as small as possible
  4. D.Join order — a distributed strategy that repartitions both inputs on the join key across nodes so matching rows land together

Answer + AI explanation with Pro

13. What is Broadcast join?

Senior
  1. A.a distributed strategy that copies a small table to every node so each can join its local partition without reshuffling
  2. B.a distributed strategy that repartitions both inputs on the join key across nodes so matching rows land together
  3. C.an algorithm that builds an in-memory hash table on one input and probes it with the other, favored for large unsorted equality joins
  4. D.the sequence in which the optimizer combines tables, chosen to keep intermediate result sizes as small as possible

Answer + AI explanation with Pro

14. Which term means: "a distributed strategy that copies a small table to every node so each can join its local partition without reshuffling"?

Senior
  1. A.Merge join
  2. B.Nested loop join
  3. C.Broadcast join
  4. D.Hash join

Answer + AI explanation with Pro

15. Which statement is correct?

Senior
  1. A.Broadcast join — an algorithm that consumes two inputs already sorted on the key and advances through them in lockstep to match rows
  2. B.Broadcast join — an algorithm that builds an in-memory hash table on one input and probes it with the other, favored for large unsorted equality joins
  3. C.Broadcast join — a distributed strategy that copies a small table to every node so each can join its local partition without reshuffling
  4. D.Broadcast join — a distributed strategy that repartitions both inputs on the join key across nodes so matching rows land together

Answer + AI explanation with Pro

16. What is Partitioned join?

Senior
  1. A.an algorithm that scans the outer input and, for each row, probes the inner input, ideal when one side is small or indexed
  2. B.an algorithm that builds an in-memory hash table on one input and probes it with the other, favored for large unsorted equality joins
  3. C.a distributed strategy that copies a small table to every node so each can join its local partition without reshuffling
  4. D.a distributed strategy that repartitions both inputs on the join key across nodes so matching rows land together

Answer + AI explanation with Pro

17. Which term means: "a distributed strategy that repartitions both inputs on the join key across nodes so matching rows land together"?

Senior
  1. A.Merge join
  2. B.Broadcast join
  3. C.Hash join
  4. D.Partitioned join

Answer + AI explanation with Pro

18. Which statement is correct?

Senior
  1. A.Partitioned join — a distributed strategy that copies a small table to every node so each can join its local partition without reshuffling
  2. B.Partitioned join — an algorithm that consumes two inputs already sorted on the key and advances through them in lockstep to match rows
  3. C.Partitioned join — an algorithm that builds an in-memory hash table on one input and probes it with the other, favored for large unsorted equality joins
  4. D.Partitioned join — a distributed strategy that repartitions both inputs on the join key across nodes so matching rows land together

Answer + AI explanation with Pro

Free to start

Start with a free readiness check

Sign up free for the 2-minute IT readiness check and a scored result. Answers, explanations and the AI tutor on every Join Algorithms question come with Pro.

Take the free IT readiness check

or take a mock interview set up for this area

24,000+ questions & coding problemsSoftware & IT16,274 questionsGovernment jobs26 examsAptitudenew questions every timeAI practice interviewwith feedback65 topics to practiseMechanical1,149 questionsGATE ME9 papersEngineering Mathematics381 questions2-minute checkfreeDSA Problems1,422Civil1,005 questionsGATE CE9 papersCS Fundamentals1,209 questionsYour scores6 skillsSystem Design25Electrical / EEE1,047 questionsGATE EE9 papersRun your codeC++ · Java · PythonLow-Level Design144Electronics & Comm.975 questionsGATE EC9 papersAI help on every questionFull-Stack6,282Chemical1,005 questionsGATE CH9 papersAI whiteboardsystem designWork abroadEurope · remote · transfersESE ME1 paperGATE practice papers2019–2026ESE CE1 paperDate alertsbefore the last dateESE EE1 paperBehavioural courseHR round practiceESE ET1 paperResume optimizerProSSC JE ME1 paperApplication trackerSSC JE CE1 paperCompany-wise prepSSC JE EE1 paperRole roadmapsRRB JE1 subjectPriced in ₹UPI · cardsISRO SC1 paperGATE CS9 papersIBPS SO IT1 paperUGC NET CS1 paperSSC CGL26 papersIBPS PO26 papersRRB NTPC26 papersSSC CHSL26 papersIBPS Clerk26 papersSBI Clerk26 papersRRB Group D26 papersSSC CPO26 papersSSC GD26 papers