Database-Management-System
August 29, 2024Database-Management-System
August 29, 2024Database-Management-System
| Question 653 |
Consider the following two commands C1 and C2 on the relation R from an SQL database:
C1 : drop table R;
C2 : delete from R;
Which of the following statements is TRUE ?
I. Both C1 and C2 delete the schema for R.
II. C2 retains relation R, but deletes all tuples in R.
III. C1 deletes not only all tuples of R, but also the schema for R.
C1 : drop table R;
C2 : delete from R;
Which of the following statements is TRUE ?
I. Both C1 and C2 delete the schema for R.
II. C2 retains relation R, but deletes all tuples in R.
III. C1 deletes not only all tuples of R, but also the schema for R.
| I only | |
| I and II only | |
| II and III only | |
| I, II and III |
Question 653 Explanation:
→ Dropping the relation means to delete the content of a table and free up the space allocated to a table.
→ Deleting the tuples means keeping the space allocated to a table/relation but deleting the data relation contains.
→ Now DELETE command is used to delete the tuples of a relation while DROP command is used to delete the schema as well as tuples of a relation.
Hence option (C) is correct.
→ Deleting the tuples means keeping the space allocated to a table/relation but deleting the data relation contains.
→ Now DELETE command is used to delete the tuples of a relation while DROP command is used to delete the schema as well as tuples of a relation.
Hence option (C) is correct.
Correct Answer: C
Question 653 Explanation:
→ Dropping the relation means to delete the content of a table and free up the space allocated to a table.
→ Deleting the tuples means keeping the space allocated to a table/relation but deleting the data relation contains.
→ Now DELETE command is used to delete the tuples of a relation while DROP command is used to delete the schema as well as tuples of a relation.
Hence option (C) is correct.
→ Deleting the tuples means keeping the space allocated to a table/relation but deleting the data relation contains.
→ Now DELETE command is used to delete the tuples of a relation while DROP command is used to delete the schema as well as tuples of a relation.
Hence option (C) is correct.