Explanation: Secondary members replicate deletion operations from the primary. 7. You can combine the ________ constraint with the sparse index to filter these null values from the unique index and avoid the error.
A. Hashed
B. Unique
C. sparse
D. compound
Answer:A
Explanation: Secondary members replicate deletion operations from the primary. 7. You can combine the ________ constraint with the sparse index to filter these null values from the unique index and avoid the error.
A. Hashed B. Unique C. sparse D. compound
Explanation:If a document does not have a value for the indexed field in a unique index, the index will store a null value for this document. 8. Which of the following method is to verify whether MongoDB used index intersection ?