Query optimization in Firebase - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is query optimization in Firebase?

Query optimization means making your database queries faster and use fewer resources by structuring them well and using indexes.

beginner

Why should you use indexes in Firebase queries?

Indexes help Firebase find data quickly without scanning the whole database, making queries faster and cheaper.

beginner

How does limiting query results improve performance?

Limiting results means Firebase sends only the needed data, reducing download time and cost.

intermediate

What is a composite index in Firebase?

A composite index is an index on multiple fields that helps optimize complex queries with multiple conditions.

intermediate

How can you avoid slow queries in Firebase?

Avoid queries that require scanning many documents without indexes, and use filters and limits to reduce data scanned.

What does adding an index to a Firebase query do?

A Deletes unnecessary data from the database

B Encrypts the data for security

C Automatically backs up your data

D Makes the query faster by helping Firebase find data quickly

Indexes speed up queries by allowing Firebase to quickly locate the requested data.

Which practice helps reduce the amount of data downloaded in a Firebase query?

A Using only one field in queries

B Fetching all documents every time

C Using limit() to restrict the number of results

D Avoiding indexes

Using limit() reduces the number of documents returned, saving bandwidth and time.

What is a composite index used for in Firebase?

A To index multiple fields for complex queries

B To store backup copies of data

C To encrypt multiple fields

D To delete multiple documents at once

Composite indexes optimize queries that filter or sort on multiple fields.

What happens if you run a query without the required index in Firebase?

A The query runs slower but returns results

B Firebase shows an error with a link to create the index

C Firebase deletes the data

D The query runs faster automatically

Firebase requires indexes for certain queries and prompts you to create them if missing.

Which of these is NOT a good practice for query optimization in Firebase?

A Scanning entire collections without indexes

B Using limit() to reduce results

C Fetching only needed fields

D Creating indexes for frequent queries

Scanning entire collections without indexes causes slow queries and high costs.

Explain how indexes improve query performance in Firebase.

Think about how a library catalog helps find books faster.

Describe three best practices to optimize Firebase queries.

Focus on reducing data scanned and transferred.