Pagination with limit and offset in Rest API - Step-by-Step Execution

Concept Flow - Pagination with limit and offset

Client sends request with limit and offset

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Server receives request

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Server extracts limit and offset

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Server queries data: skip offset, take limit

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Server sends back limited data slice

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Client displays current page data

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Client requests next/previous page with new offset

The client asks for a slice of data by sending limit and offset. The server uses these to return just that slice, enabling page-by-page data viewing.

Execution Sample

Rest API

GET /items?limit=3&offset=6

Server: SELECT * FROM items LIMIT 3 OFFSET 6

Response: items 7,8,9

Client requests 3 items starting from the 7th item (offset 6), server returns those 3 items.

Execution Table

Step	Request URL	Extracted limit	Extracted offset	Data slice returned	Explanation
1	/items?limit=3&offset=0	3	0	items 1,2,3	First page, start at item 1
2	/items?limit=3&offset=3	3	3	items 4,5,6	Second page, skip first 3 items
3	/items?limit=3&offset=6	3	6	items 7,8,9	Third page, skip first 6 items
4	/items?limit=3&offset=9	3	9	items 10	Fourth page, only one item left
5	/items?limit=3&offset=12	3	12	empty list	Offset beyond data, no items returned

💡 When offset is beyond total items, server returns empty list, ending pagination.

Variable Tracker

Variable	Start	After 1	After 2	After 3	After 4	After 5
limit	3	3	3	3	3	3
offset	0	3	6	9	12	15
data slice size	3	3	3	3	1	0

Key Moments - 3 Insights

Why does the server return fewer items on the last page?

Because the offset skips most items, and fewer than 'limit' items remain. See execution_table row 4 where only 1 item is left.

What happens if offset is larger than total items?

The server returns an empty list, meaning no data. This is shown in execution_table row 5.

Why do we use both limit and offset instead of just one?

Limit controls how many items to return, offset controls where to start. Together they let us get any page slice. See execution_table columns 'Extracted limit' and 'Extracted offset'.

Visual Quiz - 3 Questions

Look at the execution_table, what data slice is returned at step 3?

A items 4,5,6

B items 10

C items 7,8,9

D empty list

💡 Hint

Check the 'Data slice returned' column at step 3 in execution_table.

At which step does the server return an empty list?

A Step 3

B Step 5

C Step 2

D Step 4

💡 Hint

Look at the last row in execution_table where 'Data slice returned' is empty.

If the limit changes to 5, how would the data slice size change at step 2?

A It would be 5

B It would be 6

C It would be 3

D It would be 0

💡 Hint

Refer to variable_tracker 'limit' and 'data slice size' values and how limit controls slice size.

Concept Snapshot

Pagination with limit and offset:
- Client sends limit (items per page) and offset (items to skip).
- Server returns data starting at offset, up to limit items.
- Use to fetch pages of data without loading all at once.
- If offset exceeds data size, server returns empty list.
- Common in REST APIs for efficient data browsing.

Full Transcript

Pagination with limit and offset means the client asks the server for a small part of the data. The client sends two numbers: limit, how many items to get, and offset, how many items to skip first. The server uses these numbers to pick the right slice of data and sends it back. For example, if limit is 3 and offset is 6, the server sends items 7, 8, and 9. This helps show data page by page. If the offset is bigger than the data size, the server sends an empty list, meaning no more data. This way, the client can ask for pages one after another by changing the offset.