Database - The Relational Model and Normalization - Discussion
Discussion Forum : The Relational Model and Normalization - General Questions (Q.No. 12)
12.
Which of the following is not a restriction for a table to be a relation?
Discussion:
11 comments Page 1 of 2.
Muhammad Hashim said:
7 years ago
The order of tuples/rows in a relation is not important or insignificant.
Ravi said:
9 years ago
Question is confusing for me. What are they asking is a restriction that is in the definition of the table and not restricting the table to be a relation?
Another way of understanding the question is a restriction that is in the definition of a table and not in the definition of a relation.
Another way of understanding the question is a restriction that is in the definition of a table and not in the definition of a relation.
Ibrahim said:
9 years ago
Yes, D is not the correct answer. If two rows are identical, then it does not have a primary key.
Redblood said:
1 decade ago
Answer C is correct because question is Which of the following is not a restriction for a table to be a relation? (noticed that "not a restriction for a table").
But option D. No two rows in a table may be identical. Which is a restriction for table? (and question asking for not not a restriction).
So that's why D is wrong. There is no concept for ordering of column in DBMS that why option C is true?
But option D. No two rows in a table may be identical. Which is a restriction for table? (and question asking for not not a restriction).
So that's why D is wrong. There is no concept for ordering of column in DBMS that why option C is true?
Anila said:
1 decade ago
Can any one say the correct answer please it is either C or D?
Amita said:
1 decade ago
Answer is D option because a relation exits only when it follow at last 1 NF.
Neha dwl said:
1 decade ago
If two rows will be identical then it breaks the 1NF rule. It means it does not have any candidate key.
Ankush said:
1 decade ago
If two rows will be identical then it breaks the 1NF rule. It means it does not have any candidate key so table is cannot be a relation. So last d in mandatory option for a table to be a relation.
Pavan Kumar Gupta said:
1 decade ago
Columns are also known as attributes of the entity or entity set so there is no need or restriction of relational database that attribute of any entity set must be ordered.
Harshit said:
1 decade ago
I think the last option is correct. Can anybody elabotaye the thing ?
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