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@stepbystep001

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Renaming in SQL is accomplished by using
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20%
RENAME
76%
AS
2%
Name
1%
Cahnge To
Relational set operators are used to combine or subtract the records from two tables
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95%
T
5%
F
RELATIONAL SET OPERATORS is
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9%
Unary
79%
Binary
8%
Ternary
3%
Origi
RELATIONAL SET OPERATORS are used for doing set operations on relations having same schema.
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T
4%
F
...... , is a relation that includes all tuples that are either in R or in S or in both R and S. Duplicate tuples are eliminated
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92%
UNION
6%
INTERSECTION
2%
MINUS
In order to set operators to work in database, it should have same number of columns participating in the query and the datatypes of respective columns should be same is called Union Compatibility.
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T
7%
F
IN UNION Duplicate tuples are allowed.
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29%
T
71%
F
is a relation that includes all tuples that are in both R and S.
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41%
UNION
56%
INTERSECTION
3%
SET DIFFERENCE
is a relation that includes all tuples that are in R but not in S.
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4%
INTERSECTION
28%
SET DIFFERENCE
15%
MINUS
53%
MINUS و SET DIFFERENCE
R ∪ S ≠ S ∪ R
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T
87%
F
R − S ≠ S – R
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T
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F
The set operations ∪ and ∩ are ……………… but “–” is not.
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valid
2%
correct
92%
commutative
2%
available
If the cardinality of R, S and R∩S is 40, 50, and 20 respectively, then the cardinality of R∪S is 70.
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T
21%
F
R ∪ (S ∪ T) = (R ∪ S) ∪ T and (R ∩ S ) ∩ T = R ∩ (S ∩ T )
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T
9%
F
R ∩ S = ((R ∪ S ) − (R − S )) − (S − R)
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T
14%
F
For the Cartesian product to be defined, the two relations involved must have disjoint headers—that is, they must not have a common attribute name
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82%
T
18%
F
CARTESIAN PRODUCT operation applied by itself is generally meaningful .
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46%
T
54%
F
DIVISION operation is a binary relational operation that divides one set of rows into another set of rows based on specified conditions
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T
7%
F
DIVISION general form is R÷ S to apply this operation the relation S must be subset of Relation R.
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91%
T
9%
F
U = R x S then U ÷ S =
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6%
S
87%
R
8%
invalid