Stats and extended stats in Elasticsearch - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the stats aggregation in Elasticsearch provide?

The stats aggregation calculates basic statistics like count, min, max, sum, and average for numeric fields in your data.

intermediate

Name three additional metrics provided by the extended_stats aggregation beyond basic stats.

The extended_stats aggregation provides variance, standard deviation, and sum of squares in addition to count, min, max, sum, and average.

beginner

How do you specify the field to aggregate on in a stats aggregation?

You specify the field using the field parameter inside the aggregation body, for example: { "stats": { "field": "price" } }.

intermediate

What is the difference between stats and extended_stats aggregations?

stats provides basic statistics (count, min, max, sum, avg), while extended_stats adds variance, standard deviation, and sum of squares for deeper analysis.

intermediate

Why might you use extended_stats instead of stats in Elasticsearch?

Use extended_stats when you need more detailed statistical insights like how spread out your data is (standard deviation) or variance, which helps understand data variability.

Which metric is NOT provided by the stats aggregation?

A Count

B Average

C Minimum

D Sum of squares

Sum of squares is provided only by extended_stats, not by stats.

What parameter do you use to specify the numeric field for stats aggregation?

A value

B field

C metric

D type

The field parameter tells Elasticsearch which numeric field to calculate statistics on.

Which aggregation would you use to get the standard deviation of a numeric field?

A extended_stats

B terms

C avg

D stats

extended_stats includes standard deviation, while stats does not.

If you want to know how many documents have a value in a field, which metric helps you?

A count

B sum

C min

D variance

The count metric shows how many documents have a value for the field.

Which of these is NOT a valid metric returned by extended_stats?

A Variance

B Sum

C Median

D Standard deviation

Median is not provided by extended_stats; it requires a different aggregation like percentiles.

Explain what the stats aggregation does and list the basic statistics it provides.

Think about simple summary numbers that describe a set of values.

Describe the additional insights you get from extended_stats compared to stats aggregation.

Consider how to measure how data values differ from the average.