Cursor-based pagination (startAfter, endBefore) in Firebase - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is cursor-based pagination in Firebase?

Cursor-based pagination uses a specific document snapshot or field value as a marker to fetch the next set of results, allowing efficient navigation through large datasets.

beginner

What does the startAfter method do in Firebase queries?

startAfter tells Firebase to return documents after the given cursor, excluding the cursor itself, to fetch the next page of results.

intermediate

How does endBefore differ from startAfter in Firebase pagination?

endBefore returns documents before the given cursor, excluding the cursor, useful for fetching previous pages in reverse order.

intermediate

Why is cursor-based pagination preferred over offset-based pagination in Firebase?

Cursor-based pagination is faster and more reliable because it uses document snapshots or values as markers, avoiding performance issues and inconsistencies caused by skipping documents.

beginner

What is required to use startAfter or endBefore in a Firebase query?

You need a valid cursor, which can be a document snapshot or a field value from a previous query result, to mark where to start or end the next query.

What does startAfter do in Firebase pagination?

A Returns all documents ignoring the cursor

B Returns documents starting exactly at the cursor

C Returns documents before the cursor, including it

D Returns documents after the cursor, excluding it

startAfter fetches documents after the cursor, excluding the cursor itself.

Which method would you use to fetch documents before a certain point in Firebase?

A endBefore

B limit

C startAfter

D orderBy

endBefore returns documents before the given cursor.

Why is cursor-based pagination better than offset-based pagination in Firebase?

A It requires no query parameters

B It uses less memory

C It avoids skipping documents and is more efficient

D It loads all documents at once

Cursor-based pagination uses document snapshots or values to avoid skipping and improves query performance.

What can be used as a cursor in Firebase pagination?

A A random number

B A document snapshot

C A collection name

D A query limit

A document snapshot or a field value from a previous query is used as a cursor.

If you want to get the next page of results after a known document, which method should you use?

A startAfter

B orderByDescending

C limitToLast

D endBefore

startAfter fetches documents after the given cursor for the next page.

Explain how cursor-based pagination works in Firebase using startAfter and endBefore.

Think about how you mark your place in a book to continue reading.

Why should you prefer cursor-based pagination over offset-based pagination in Firebase?

Consider how skipping pages in a book might cause confusion.