Pagination pattern with skip and limit in MongoDB - Step-by-Step Execution

Concept Flow - Pagination pattern with skip and limit

Start Query

↓

Apply skip(n)

↓

Apply limit(m)

↓

Return m documents starting from n+1

↓

Display Page Results

↓

User requests next page?

Yes→Increase skip by m

No↓

End

The query skips a number of documents, then limits the result to a page size, returning that page's documents. User can request next page by increasing skip.

Execution Sample

MongoDB

db.collection.find().skip(5).limit(3)

This query skips the first 5 documents and returns the next 3 documents as a page.

Execution Table

Step	Action	Documents Skipped	Documents Returned	Resulting Documents
1	Start query on collection with 10 documents	0	0	[doc1, doc2, doc3, doc4, doc5, doc6, doc7, doc8, doc9, doc10]
2	Apply skip(5)	5	0	[doc6, doc7, doc8, doc9, doc10]
3	Apply limit(3)	5	3	[doc6, doc7, doc8]
4	Return results	5	3	[doc6, doc7, doc8]
5	User requests next page, increase skip to 8	8	0	[doc9, doc10]
6	Apply limit(3) on new skip	8	2	[doc9, doc10]
7	Return results for next page	8	2	[doc9, doc10]
8	No more documents to fetch, end pagination	10	0	[]

💡 No more documents after skipping 10, so pagination ends.

Variable Tracker

Variable	Start	After Step 2	After Step 3	After Step 5	After Step 6	Final
skip	0	5	5	8	8	10
limit	3	3	3	3	3	3
documents_skipped	0	5	5	8	8	10
documents_returned	0	0	3	0	2	0
resulting_documents	[doc1..doc10]	[doc6..doc10]	[doc6, doc7, doc8]	[doc9, doc10]	[doc9, doc10]	[]

Key Moments - 3 Insights

Why does the query skip documents before limiting?

Because skip(n) moves the cursor past the first n documents, so limit(m) returns the next m documents after skipping. See execution_table rows 2 and 3.

What happens if skip is larger than the total documents?

No documents are returned because the cursor moves past all documents. See execution_table row 8 where skip=10 returns empty.

Why does increasing skip by limit give the next page?

Because each page shows 'limit' documents, increasing skip by that amount moves to the next set. See execution_table rows 5 and 6.

Visual Quiz - 3 Questions

Look at the execution_table, what documents are returned at Step 3?

A [doc1, doc2, doc3]

B [doc9, doc10]

C [doc6, doc7, doc8]

D []

💡 Hint

Check the 'Resulting Documents' column at Step 3 in the execution_table.

At which step does the condition 'no more documents to fetch' become true?

A Step 4

B Step 8

C Step 7

D Step 2

💡 Hint

Look for the step where the resulting documents are empty in the execution_table.

If limit was changed to 2, how many documents would be returned at Step 3?

A 2

B 3

C 5

D 0

💡 Hint

Refer to variable_tracker for 'limit' and how it affects documents returned.

Concept Snapshot

Pagination with skip and limit:
- Use skip(n) to skip first n documents
- Use limit(m) to get next m documents
- Combine to get pages: skip = page_number * m
- If skip > total docs, returns empty
- Good for small pages, but large skip can be slow

Full Transcript

This visual execution shows how MongoDB pagination works using skip and limit. The query first skips a number of documents, then limits the output to a page size. For example, skip(5) and limit(3) returns documents 6, 7, and 8. Increasing skip by the limit value fetches the next page. If skip exceeds the total documents, no results are returned, ending pagination. This pattern helps show data page by page.