The MongoDB Aggregation Framework | Chapter 4 - Core Aggregation - Multidimensional Grouping
In this article i am gone to share MongoDB-University Course:
The MongoDB Aggregation Framework | Chapter 4 - Core Aggregation -
Multidimensional Grouping Quiz Answer with you..
Facets: Single Facet Query
Which of the following aggregation pipelines are single facet
queries?
[
{"$match": { "$text": {"$search": "network"}}},
{"$sortByCount": "$offices.city"},
]
[
{"$unwind": "$offices"},
{"$project": { "_id": "$name", "hq": "$offices.city"}},
{"$sortByCount": "$hq"},
{"$sort": {"_id":-1}},
{"$limit": 100}
]
[
{"$match": { "$text": {"$search": "network"}}},
{"$unwind": "$offices"},
{"$sort": {"_id":-1}}
]
Facets: Manual Buckets
Assuming that field1 is composed of double values, ranging between 0
and Infinity, and field2 is of type string, which of the following
stages are correct?
- {'$bucket': { 'groupBy': '$field1', 'boundaries': [ 0.4, Infinity ]}}
- {'$bucket': { 'groupBy': '$field1', 'boundaries': [ "a", 3, 5.5 ]}}
- {'$bucket': { 'groupBy': '$field2', 'boundaries': [ "a", "asdas", "z" ], 'default': 'Others'}}
Facets: Auto Buckets
Auto Bucketing will ...
- adhere bucket boundaries to a numerical series set by the granularity option.
- randomly distributed documents accross arbitrarily defined bucket boundaries.
- given a number of buckets, try to distribute documents evenly accross buckets.
- count only documents that contain the groupBy field defined in the documents.
Facets: Multiple Facets
Which of the following statement(s) apply to the $facet stage?
- The $facet stage allows several sub-pipelines to be executed to produce multiple facets.
- The $facet stage allows the application to generate several different facets with one single database request.
- The output of the individual facetsub − pipelinescanbesharedusingtheexpression $FACET.$.
- We can only use facets stages ($sortByCount, $bucket and $bucketAuto) as sub-pipelines of $facet stage.
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