Explanation:The aggregation framework enables users to obtain the kind of results for which the SQL GROUP BY clause is used. 8. MongoDB supports fixed-size collections called ____________ collections.
A. primary
B. secondary
C. capped
D. All of the mentioned
Answer:A
Explanation:The aggregation framework enables users to obtain the kind of results for which the SQL GROUP BY clause is used. 8. MongoDB supports fixed-size collections called ____________ collections.
A. primary B. secondary C. capped D. All of the mentioned
Explanation:This type of collection maintains insertion order and, once the specified size has been reached, behaves like a circular queue. 9. MongoDB uses a ____________ lock that allows concurrent read access to a database but exclusive write access to a single write operation.