Supabase Database Deadlock detected error when two transactions are waiting for each other to release locks.

Deadlock occurs due to circular dependencies in transaction logic.

Understanding Supabase Database

Supabase is an open-source backend-as-a-service platform that provides developers with a suite of tools to build applications quickly. It offers a PostgreSQL database, authentication, storage, and real-time capabilities, making it a popular choice for modern web and mobile applications. The database component is particularly powerful, leveraging PostgreSQL's robust features.

Identifying the Symptom

When working with Supabase Database, you might encounter the error code 40P01, which indicates a 'Deadlock detected' error. This typically occurs when two or more transactions are waiting for each other to release locks, causing a standstill.

What You Might Observe

In your application logs or Supabase console, you may see an error message similar to:

ERROR: deadlock detected
DETAIL: Process 1234 waits for ShareLock on transaction 5678; blocked by process 5678.

This indicates that a deadlock situation has been detected, and the database has chosen to terminate one of the transactions to break the deadlock.

Explaining the Issue

The 40P01 error code is specific to PostgreSQL and indicates a deadlock situation. Deadlocks occur when two or more transactions are waiting for each other to release locks on resources, creating a cycle of dependencies that cannot be resolved without intervention.

Common Causes of Deadlocks

  • Transactions acquiring locks in different orders.
  • Long-running transactions holding locks for extended periods.
  • Complex transaction logic with multiple dependencies.

Steps to Fix the Issue

Resolving deadlocks involves reviewing and optimizing your transaction logic. Here are some actionable steps:

1. Analyze Transaction Dependencies

Review your transaction logic to identify potential circular dependencies. Ensure that transactions acquire locks in a consistent order to prevent deadlocks.

2. Use Shorter Transactions

Minimize the duration of transactions by breaking them into smaller, more manageable units. This reduces the likelihood of deadlocks and improves overall performance.

3. Implement Retry Logic

Incorporate retry logic in your application to handle deadlock errors gracefully. For example, using a retry mechanism with exponential backoff can help:

function executeTransaction() {
let attempts = 0;
const maxAttempts = 5;
while (attempts < maxAttempts) {
try {
// Execute transaction logic
break;
} catch (error) {
if (error.code === '40P01') {
attempts++;
// Wait before retrying
continue;
}
throw error;
}
}
}

4. Monitor and Optimize Queries

Use Supabase's query performance tools to monitor and optimize your queries. Ensure that indexes are used effectively to reduce lock contention. For more information, refer to the Supabase Performance Guide.

Conclusion

Deadlocks can be challenging, but with careful analysis and optimization of your transaction logic, you can minimize their occurrence. By following the steps outlined above, you can ensure smoother operation of your Supabase Database and improve the reliability of your applications.

For further reading on PostgreSQL deadlocks, visit the PostgreSQL Documentation.

Master

Supabase Database

in Minutes — Grab the Ultimate Cheatsheet

(Perfect for DevOps & SREs)

Most-used commands
Real-world configs/examples
Handy troubleshooting shortcuts
Your email is safe with us. No spam, ever.

Thankyou for your submission

We have sent the cheatsheet on your email!
Oops! Something went wrong while submitting the form.

Supabase Database

Cheatsheet

(Perfect for DevOps & SREs)

Most-used commands
Your email is safe with us. No spam, ever.

Thankyou for your submission

We have sent the cheatsheet on your email!
Oops! Something went wrong while submitting the form.

MORE ISSUES

Made with ❤️ in Bangalore & San Francisco 🏢

Doctor Droid