Pagination (from/size) in Elasticsearch - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to set the starting point for pagination in Elasticsearch.

Elasticsearch

{
  "from": [1],
  "size": 10
}

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

A0

B10

C5

D20

Attempts:

3 left

💡 Hint

Common Mistakes

Using 1 instead of 0 for the first result index.

Confusing from with size.

The from parameter sets the starting index for the search results. To start from the first result, use 0.

2fill in blank

medium

Complete the code to set the number of results per page in Elasticsearch.

Elasticsearch

{
  "from": 0,
  "size": [1]
}

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

A20

B10

C15

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Setting size to 0 or a negative number.

Confusing size with from.

The size parameter controls how many results are returned per page. Here, it is set to 10.

3fill in blank

hard

Fix the error in the pagination code to correctly get the second page with 10 results per page.

Elasticsearch

{
  "from": [1],
  "size": 10
}

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

A10

B20

C1

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using 1 instead of 10 for the second page.

Setting from to 0 for the second page.

To get the second page with 10 results per page, from should be 10 (skip the first 10 results).

4fill in blank

hard

Fill both blanks to get the third page with 15 results per page.

Elasticsearch

{
  "from": [1],
  "size": [2]
}

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

A30

B15

C10

D20

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up from and size values.

Using incorrect multiplication for from.

For the third page with 15 results per page, from is (3 - 1) * 15 = 30, and size is 15.

5fill in blank

hard

Fill all three blanks to get the fourth page with 20 results per page and start from the correct offset.

Elasticsearch

{
  "from": [1],
  "size": [2],
  "query": {
    "match_all": [3]
  }
}

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

A60

B20

C{}

D40

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong from value for the page.

Setting match_all to null or missing braces.

For the fourth page with 20 results per page, from is (4 - 1) * 20 = 60, size is 20, and match_all requires an empty object {}.

Practice

1.

What does the from parameter control in an Elasticsearch query?

easy

A. The total number of results to return

B. The starting index of the search results to return

C. The sorting order of the results

D. The fields to include in the results

Solution

1. Step 1: Understand the role of from

   The from parameter sets the offset, meaning it tells Elasticsearch where to start returning results from.

2. Step 2: Differentiate from size

   The size parameter controls how many results to return, not the starting point.

3. Final Answer:

   The starting index of the search results to return -> Option B

4. Quick Check:

   from = start index [OK]

Hint: Remember: from = start index, size = count [OK]

Common Mistakes:

• Confusing from with size
• Thinking from controls sorting
• Assuming from limits total results

2.

Which of the following is the correct way to request the second page of results with 10 items per page using from and size?

{ "from": ?, "size": 10 }

easy

A. 10

B. 1

C. 11

D. 20

Solution

1. Step 1: Calculate the starting index for page 2

   Page 1 has items 0-9, so page 2 starts at index 10 (10 items per page).

2. Step 2: Set from to 10 and size to 10

   This returns items 10 to 19, which is the second page.

3. Final Answer:

   10 -> Option A

4. Quick Check:

   Page 2 start = (2-1)*10 = 10 [OK]

Hint: from = (page_number - 1) * size [OK]

Common Mistakes:

• Using 1 instead of 10 for from
• Using 11 which skips one item
• Using 20 which is page 3 start

3.

Given this Elasticsearch query snippet, what range of results will be returned?

{ "from": 5, "size": 3 }

medium

A. Results 3 to 5

B. Results 0 to 3

C. Results 5 to 7

D. Results 6 to 8

Solution

1. Step 1: Identify the starting index

   The from value is 5, so results start from index 5.

2. Step 2: Calculate the ending index

   With size 3, results include indexes 5, 6, and 7.

3. Final Answer:

   Results 5 to 7 -> Option C

4. Quick Check:

   from=5, size=3 -> 5,6,7 [OK]

Hint: from + size - 1 = last result index [OK]

Common Mistakes:

• Assuming from is count, not start
• Off-by-one errors in range
• Mixing up start and end indexes

4.

Identify the error in this Elasticsearch pagination query:

{ "from": -5, "size": 10 }

medium

A. "from" must be zero or positive, but negative is allowed

B. "size" must be less than 10

C. No error, this query is valid

D. "from" cannot be negative

Solution

1. Step 1: Check the value of from

   The from parameter must be zero or positive; negative values are invalid.

2. Step 2: Validate size value

   The size value 10 is valid and does not cause error.

3. Final Answer:

   "from" cannot be negative -> Option D

4. Quick Check:

   Negative from is invalid [OK]

Hint: from must be ≥ 0, negative causes error [OK]

Common Mistakes:

• Allowing negative from values
• Confusing size limits
• Ignoring validation rules

5.

You want to display search results page by page with 15 results each. If the user requests page 4, what should the from and size values be to get the correct results?

hard

A. { "from": 45, "size": 15 }

B. { "from": 60, "size": 15 }

C. { "from": 30, "size": 15 }

D. { "from": 15, "size": 4 }

Solution

1. Step 1: Calculate the starting index for page 4

   Using the formula from = (page_number - 1) * size, we get (4 - 1) * 15 = 45.

2. Step 2: Set the size to 15

   Since each page shows 15 results, size remains 15.

3. Final Answer:

   { "from": 45, "size": 15 } -> Option A

4. Quick Check:

   from = 45, size = 15 for page 4 [OK]

Hint: Use from = (page-1)*size for correct pagination [OK]

Common Mistakes:

• Using from = page * size
• Swapping from and size values
• Setting size to page number