Explanation:Distinct keyword is used to select only unique items from the relation. 4. All aggregate functions except _____ ignore null values in their input collection.
A. Count(attribute)
B. Count(*)
C. Avg
D. Sum
Answer:A
Explanation:Distinct keyword is used to select only unique items from the relation. 4. All aggregate functions except _____ ignore null values in their input collection.
A. Count(attribute) B. Count(*) C. Avg D. Sum
Explanation:* is used to select all values including null. 5. A Boolean data type that can take values true, false, and________ .