Stats and extended stats in Elasticsearch - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to calculate basic statistics on the field 'price'.

Elasticsearch

{
  "aggs": {
    "price_stats": {
      "stats": {
        "field": "[1]"
      }
    }
  }
}

Drag options to blanks, or click blank then click option'

Auser

Bquantity

Cdate

Dprice

Attempts:

3 left

💡 Hint

Common Mistakes

Using a non-numeric field like 'date' or 'user' causes errors.

Leaving the field name blank results in no aggregation.

The 'stats' aggregation requires the field name to calculate statistics. Here, 'price' is the correct field.

2fill in blank

medium

Complete the code to calculate extended statistics on the field 'score'.

Elasticsearch

{
  "aggs": {
    "score_extended_stats": {
      "extended_stats": {
        "field": "[1]"
      }
    }
  }
}

Drag options to blanks, or click blank then click option'

Aage

Bscore

Cname

Dtimestamp

Attempts:

3 left

💡 Hint

Common Mistakes

Selecting a non-numeric field causes aggregation failure.

Using a field unrelated to the data context leads to meaningless results.

The 'extended_stats' aggregation calculates detailed stats on a numeric field. 'score' is the correct numeric field here.

3fill in blank

hard

Fix the error in the aggregation by completing the missing field name.

Elasticsearch

{
  "aggs": {
    "sales_stats": {
      "stats": {
        "field": "[1]"
      }
    }
  }
}

Drag options to blanks, or click blank then click option'

Asales_amount

Bsales_date

Ccustomer_name

Dregion

Attempts:

3 left

💡 Hint

Common Mistakes

Using a date or string field causes aggregation errors.

Leaving the field empty results in no output.

The 'stats' aggregation requires a numeric field. 'sales_amount' is numeric, while others are not.

4fill in blank

hard

Fill both blanks to calculate extended stats on 'temperature' and filter values greater than 20.

Elasticsearch

{
  "aggs": {
    "temp_stats": {
      "extended_stats": {
        "field": "[1]"
      }
    },
    "filtered_temps": {
      "filter": {
        "range": {
          "[2]": {
            "gt": 20
          }
        }
      }
    }
  }
}

Drag options to blanks, or click blank then click option'

Atemperature

Bhumidity

Dpressure

Attempts:

3 left

💡 Hint

Common Mistakes

Using different fields for aggregation and filter causes inconsistent results.

Selecting non-numeric fields for stats or range filter causes errors.

The aggregation and filter both use the 'temperature' field to calculate stats and filter values greater than 20.

5fill in blank

hard

Fill all three blanks to create an extended stats aggregation on 'duration', include a filter for values less than 100, and name the aggregation 'duration_stats'.

Elasticsearch

{
  "aggs": {
    "[1]": {
      "extended_stats": {
        "field": "[2]"
      }
    },
    "filtered_duration": {
      "filter": {
        "range": {
          "[3]": {
            "lt": 100
          }
        }
      }
    }
  }
}

Drag options to blanks, or click blank then click option'

Aduration_stats

Bduration

Dtime

Attempts:

3 left

💡 Hint

Common Mistakes

Mismatching aggregation name and field names causes confusion.

Using different fields for aggregation and filter leads to incorrect results.

The aggregation is named 'duration_stats', operates on the 'duration' field, and the filter also applies to 'duration' values less than 100.

Practice

1. What does the stats aggregation in Elasticsearch provide by default?

easy

A. Count, min, max, avg, and sum

B. Variance and standard deviation

C. Sum of squares only

D. Median and mode

Solution

1. Step 1: Understand the purpose of stats aggregation

   The stats aggregation provides basic statistical data about numeric fields.

2. Step 2: Identify the default metrics included

   By default, it returns count, min, max, avg, and sum values.

3. Final Answer:

   Count, min, max, avg, and sum -> Option A

4. Quick Check:

   Stats aggregation = basic stats [OK]

Hint: Stats aggregation gives basic stats like count and sum [OK]

Common Mistakes:

• Confusing stats with extended_stats
• Thinking stats includes variance
• Assuming median is included

2. Which of the following is the correct syntax to add an extended stats aggregation named my_stats on the field price?

easy

A. { "aggs": { "my_stats": { "extended_stats": { "field": "price" } } } }

B. { "aggs": { "my_stats": { "stats": { "field": "price" } } } }

C. { "aggs": { "my_stats": { "extended_stats": { "field_name": "price" } } } }

D. { "aggregations": { "my_stats": { "stats": { "field": "price" } } } }

Solution

1. Step 1: Check the aggregation type and field key

   The aggregation type must be extended_stats and the field key must be field.

2. Step 2: Verify the JSON structure

   The correct syntax uses aggs as the root key for aggregations, not aggregations.

3. Final Answer:

   { "aggs": { "my_stats": { "extended_stats": { "field": "price" } } } } -> Option A

4. Quick Check:

   Use extended_stats with field inside aggs [OK]

Hint: Use "aggs" and "extended_stats" with "field" key [OK]

Common Mistakes:

• Using "field_name" instead of "field"
• Using "aggregations" instead of "aggs"
• Confusing stats with extended_stats

3. Given this Elasticsearch aggregation query:

{
  "aggs": {
    "price_stats": {
      "extended_stats": {
        "field": "price"
      }
    }
  }
}

Which of the following metrics will NOT be included in the response?

medium

A. Sum of squares

B. Median

C. Standard deviation

D. Variance

Solution

1. Step 1: Identify metrics returned by extended_stats

   The extended_stats aggregation returns count, min, max, avg, sum, sum_of_squares, variance, and std_deviation.

2. Step 2: Check which metric is missing

   Median is not included in either stats or extended_stats aggregations.

3. Final Answer:

   Median -> Option B

4. Quick Check:

   Median not in extended_stats [OK]

Hint: Extended stats exclude median, include variance and std deviation [OK]

Common Mistakes:

• Assuming median is part of extended_stats
• Confusing sum_of_squares with sum
• Thinking variance is not included

4. You wrote this aggregation:

{
  "aggs": {
    "my_stats": {
      "extended_stats": {
        "field_name": "age"
      }
    }
  }
}

Why does this query fail?

medium

A. The aggregation name cannot be "my_stats"

B. The root key should be "aggregations" instead of "aggs"

C. extended_stats does not support the field "age"

D. The field key should be "field", not "field_name"

Solution

1. Step 1: Check the field key in extended_stats

   The correct key to specify the field is field, not field_name.

2. Step 2: Verify other parts of the query

   The aggregation name "my_stats" is valid, and "aggs" is the correct root key. The field "age" can be used if it exists.

3. Final Answer:

   The field key should be "field", not "field_name" -> Option D

4. Quick Check:

   Use "field" key for field name [OK]

Hint: Use "field" key, not "field_name" in aggregations [OK]

Common Mistakes:

• Using "field_name" instead of "field"
• Changing aggregation root key incorrectly
• Assuming field name is invalid without checking

5. You want to find the average price and also understand the price spread using variance and standard deviation in one query. Which aggregation setup is best?

hard

A. Use stats aggregation on price

B. Use percentiles aggregation on price

C. Use extended_stats aggregation on price

D. Use terms aggregation on price

Solution

1. Step 1: Identify metrics needed

   You want average, variance, and standard deviation, which describe spread and central tendency.

2. Step 2: Choose aggregation that provides all metrics

   extended_stats provides avg, variance, std_deviation, sum_of_squares, and more in one aggregation.

3. Step 3: Compare other options

   stats lacks variance and std deviation; terms groups data; percentiles gives percentile info, not variance.

4. Final Answer:

   Use extended_stats aggregation on price -> Option C

5. Quick Check:

   Extended stats = avg + variance + std deviation [OK]

Hint: Extended stats give avg and spread metrics together [OK]

Common Mistakes:

• Using stats and missing variance
• Confusing terms with stats
• Choosing percentiles for variance