Question
a.
If the output collection does not exist, MongoDB creates and shards the collection on the _id field
b.
Map-reduce supports operations on sharded collections, both as an input and as an output
c.
mongos dispatches, in parallel, a map-reduce post-processing job to every shard that owns a chunk
d.
None of the mentioned
Posted under MongoDB
Engage with the Community - Add Your Comment
Confused About the Answer? Ask for Details Here.
Know the Explanation? Add it Here.
Q. Point out the wrong statement.
Similar Questions
Discover Related MCQs
Q. Which of the following function follows the reduce method and modifies the output?
View solution
Q. __________ specifies global variables that are accessible in the map.
View solution
Q. MongoDB converts the JavaScript objects emitted by the map function to ________ objects.
View solution
Q. You can only use jsMode for result sets with fewer than 500,000 distinct key arguments to the mapper’s _______ function.
View solution
Q. Which of the following mode defaults to false?
View solution
Q. $dayOfMonth returns the day of the month for a date as a number between ________________
View solution
Q. Point out the wrong statement.
View solution
Q. __________ returns the day of the year for a date as a number between 1 and 366.
View solution
Q. Which of the following returns year for particular date?
View solution
Q. Point out the wrong statement.
View solution
Q. Which of the following returns the hour for a date as a number between 0 and 23?
View solution
Q. __________ returns the date as a formatted string.
View solution
Q. _______ result encompasses instances of undefined values or missing fields.
View solution
Q. ___________ returns either the non-null result of the first expression.
View solution
Q. __________ take as input a single expression, evaluating the expression once for each input document, and maintain their state for the group of documents.
View solution
Q. $sum is an accumulator operator available only in the _______ stage.
View solution
Q. Point out the wrong statement.
View solution
Q. Which of the following ignores non numeric values?
View solution
Q. When using $first in a $group stage, the $group stage should follow a _______ stage to have the input documents in a defined order.
View solution
Q. Which of the following returns the value that results from applying an expression to the last document?
View solution
Suggested Topics
Are you eager to expand your knowledge beyond MongoDB? We've curated a selection of related categories that you might find intriguing.
Click on the categories below to discover a wealth of MCQs and enrich your understanding of Computer Science. Happy exploring!