Explanation:yyyy/mm/dd is the default format in sql . 2. An ________ on an attribute of a relation is a data structure that allows the database system to find those tuples in the relation that have a specified value for that attribute efficiently, without scanning through all the tuples of the relation.
A. Index
B. Reference
C. Assertion
D. Timestamp
Answer:A
Explanation:yyyy/mm/dd is the default format in sql . 2. An ________ on an attribute of a relation is a data structure that allows the database system to find those tuples in the relation that have a specified value for that attribute efficiently, without scanning through all the tuples of the relation.
A. Index B. Reference C. Assertion D. Timestamp
Explanation:Index is the reference to the tuples in a relation. 3. Create index studentID_index on student(ID);