Bucket aggregations (terms, histogram) in Elasticsearch - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a terms aggregation in Elasticsearch?

A terms aggregation groups documents by unique values in a field, like sorting items into buckets based on categories or tags.

beginner

How does a histogram aggregation work?

It groups numeric values into fixed-size intervals (buckets), like putting ages into ranges: 0-10, 11-20, etc.

intermediate

What is the purpose of the size parameter in a terms aggregation?

It limits how many top unique terms (buckets) to return, like showing only the top 5 most common categories.

intermediate

In a histogram aggregation, what does the interval parameter control?

It sets the width of each bucket, deciding how big each numeric range is, like grouping sales by every $100.

advanced

Can you combine bucket aggregations in Elasticsearch?

Yes, you can nest bucket aggregations to group data in multiple layers, like grouping by category then by price ranges.

What does a terms aggregation group documents by?

A Unique values in a field

B Fixed numeric ranges

C Document length

D Date ranges

Terms aggregation groups documents by unique values in a specified field.

Which parameter controls the number of buckets returned in a terms aggregation?

A size

B interval

C from

D order

The size parameter limits how many top buckets are returned.

What does the histogram aggregation's interval parameter define?

A Number of buckets

B Bucket size (range width)

C Sorting order

D Field name

Interval sets the width of each numeric bucket.

Which aggregation would you use to group documents by price ranges?

A terms aggregation

B filter aggregation

C histogram aggregation

D date histogram

Histogram aggregation groups numeric values into ranges, perfect for price ranges.

Can bucket aggregations be nested inside each other?

A No, only one level allowed

B Only for terms aggregation

C Only for histogram aggregation

D Yes, to create multi-level grouping

Bucket aggregations can be nested to group data in multiple layers.

Explain how terms and histogram bucket aggregations differ and give a real-life example for each.

Think about sorting items by category vs. grouping numbers into intervals.

Describe how you would use nested bucket aggregations to analyze sales data by region and price range.

Imagine sorting sales first by location, then by price groups.