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.
A. readers
B. readers-writer
C. writer
D. None of the mentioned
Answer:A
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.
A. readers B. readers-writer C. writer D. None of the mentioned
Explanation:Before version 2.2, this lock was implemented on a per-mongod basis. Since version 2.2, the lock has been implemented at the database level. 10. Which of the following sorting is not supported by MongoDB ?