Why Supabase is the open-source Firebase alternative - Performance Analysis

Time Complexity: Why Supabase is the open-source Firebase alternative

O(1)

Understanding Time Complexity

We want to understand how the work Supabase does grows as we add more data or users.

How does Supabase handle more requests or bigger databases over time?

Scenario Under Consideration

Analyze the time complexity of fetching user data and inserting new records.

const { data, error } = await supabase
  .from('users')
  .select('*')
  .eq('active', true)
  .limit(10)

const { data: insertData, error: insertError } = await supabase
  .from('messages')
  .insert([{ user_id: userId, content: message }])

This code fetches up to 10 active users and inserts a new message record.

Identify Repeating Operations

Look at the main actions that happen repeatedly as data grows.

• Primary operation: Database queries to fetch and insert data.
• How many times: Each fetch or insert is one API call, but fetching can return multiple rows.

How Execution Grows With Input

As the number of users or messages grows, the time to fetch or insert changes.

Input Size (n)	Approx. API Calls/Operations
10	1 fetch call returning 10 rows, 1 insert call
100	1 fetch call (if limited), 1 insert call
1000	1 fetch call (still limited), 1 insert call

Pattern observation: Number of API calls stays the same due to limits, but data size returned can grow if limits increase.

Final Time Complexity

Time Complexity: O(1)

This means the number of API calls does not grow with the total data size because of query limits.

Common Mistake

[X] Wrong: "Fetching more users always means more API calls."

[OK] Correct: Because you can limit results in one call, the number of calls can stay the same even if data grows.

Interview Connect

Understanding how API calls scale helps you design efficient apps and explain your choices clearly.

Self-Check

"What if we removed the limit on fetching users? How would the time complexity change?"

Practice

1. What is one main reason Supabase is considered an alternative to Firebase?

easy

A. It is open-source and uses PostgreSQL as its database.

B. It only supports NoSQL databases.

C. It requires proprietary software licenses.

D. It does not provide real-time features.

Solution

1. Step 1: Understand Supabase's core features

   Supabase is known for being open-source and using PostgreSQL, a popular SQL database.

2. Step 2: Compare with Firebase

   Firebase is proprietary and uses NoSQL, while Supabase offers an open-source alternative with SQL.

3. Final Answer:

   It is open-source and uses PostgreSQL as its database. -> Option A

4. Quick Check:

   Open-source + PostgreSQL = C [OK]

Hint: Remember Supabase is open-source with SQL, unlike Firebase [OK]

Common Mistakes:

• Thinking Supabase only supports NoSQL
• Assuming Supabase is proprietary
• Believing Supabase lacks real-time features

2. Which of the following is the correct way to initialize a Supabase client in JavaScript?

easy

A. const supabase = createSupabase('url', 'key');

B. const supabase = createClient('url', 'key');

C. const supabase = supabase.create('url', 'key');

D. const supabase = supabaseClient('url', 'key');

Solution

1. Step 1: Recall Supabase client initialization syntax

   The official method is using createClient with URL and key as arguments.

2. Step 2: Check each option

   Only const supabase = createClient('url', 'key'); uses the correct function name and syntax.

3. Final Answer:

   const supabase = createClient('url', 'key'); -> Option B

4. Quick Check:

   createClient() is correct method [OK]

Hint: Look for createClient function with two string arguments [OK]

Common Mistakes:

• Using incorrect function names like supabaseClient or createSupabase
• Calling create as a method on supabase
• Mixing up argument order or missing quotes

3. Given this Supabase query in JavaScript:

const { data, error } = await supabase
  .from('users')
  .select('*')
  .eq('active', true);

What does data contain after execution?

medium

A. All users regardless of 'active' status.

B. An error object because the query is invalid.

C. All users where the 'active' field is true.

D. Only users where 'active' is false.

Solution

1. Step 1: Analyze the query filters

   The query selects all columns from 'users' where 'active' equals true.

2. Step 2: Understand the result

   The data variable holds the filtered list of users with active status true.

3. Final Answer:

   All users where the 'active' field is true. -> Option C

4. Quick Check:

   Filter .eq('active', true) returns active users [OK]

Hint: .eq('active', true) filters active users only [OK]

Common Mistakes:

• Assuming it returns all users without filtering
• Thinking it returns users with active false
• Believing the query causes an error

4. You wrote this Supabase query but get an error:

const { data, error } = await supabase
  .from('profiles')
  .select('id, name, email')
  .eq('verified', 'true');

What is the likely cause of the error?

medium

A. The 'verified' field is boolean but compared to string 'true'.

B. The table name 'profiles' is misspelled.

C. The select statement is missing parentheses.

D. Supabase does not support .eq() filters.

Solution

1. Step 1: Check data type mismatch in filter

   The query compares 'verified' boolean field to string 'true', causing type mismatch.

2. Step 2: Validate other parts

   Table name and select syntax are correct; .eq() is supported.

3. Final Answer:

   The 'verified' field is boolean but compared to string 'true'. -> Option A

4. Quick Check:

   Boolean compared to string causes error [OK]

Hint: Match filter value type to column type (boolean vs string) [OK]

Common Mistakes:

• Assuming .eq() is unsupported
• Thinking select needs parentheses
• Ignoring data type mismatch in filters

5. You want to avoid vendor lock-in by using Supabase instead of Firebase. Which feature of Supabase helps most with this?

hard

A. It stores data in a custom binary format.

B. It only works with proprietary cloud services.

C. It requires you to use Firebase SDKs.

D. It is open-source and uses a standard PostgreSQL database.

Solution

1. Step 1: Understand vendor lock-in

   Vendor lock-in happens when you depend on proprietary tech that is hard to move from.

2. Step 2: Identify Supabase's advantage

   Supabase is open-source and uses PostgreSQL, a widely supported standard database, easing migration.

3. Final Answer:

   It is open-source and uses a standard PostgreSQL database. -> Option D

4. Quick Check:

   Open-source + PostgreSQL = less lock-in [OK]

Hint: Open-source + standard DB = easy to switch later [OK]

Common Mistakes:

• Thinking Supabase requires Firebase SDKs
• Believing it uses proprietary cloud only
• Assuming data is stored in custom formats