canceling statement due to user request

This error occurs when a query is manually canceled or exceeds a timeout limit. Learn about statement timeouts and query optimization.

The canceling statement due to user request error means the query was stopped before completion.

Understanding the Error

ERROR: canceling statement due to user request

The query was terminated, either manually or by a timeout.

Common Causes

1. Manual Cancellation

User pressed Ctrl+C or clicked cancel in a database tool.

2. Statement Timeout

SQL

-- Query exceeded statement_timeout
SET statement_timeout = '5s';
SELECT * FROM huge_table;  -- Takes too long, gets canceled

3. Application Timeout

Application closed the connection before query finished.

4. Connection Pool Timeout

Connection pool reclaimed the connection.

How to Fix It

Solution 1: Increase Statement Timeout

SQL

-- Per session
SET statement_timeout = '60s';

-- For a specific query
SET LOCAL statement_timeout = '300s';
SELECT * FROM huge_table;
RESET statement_timeout;

Solution 2: Optimize the Query

SQL

-- Add indexes
CREATE INDEX idx_orders_date ON orders(created_at);

-- Use LIMIT
SELECT * FROM huge_table LIMIT 1000;

-- Add WHERE clause
SELECT * FROM orders WHERE created_at > '2024-01-01';

Solution 3: Check Query Performance

SQL

-- Analyze query execution plan
EXPLAIN ANALYZE SELECT * FROM huge_table WHERE status = 'active';

-- Identify slow parts
EXPLAIN (ANALYZE, BUFFERS, FORMAT TEXT)
SELECT * FROM orders o
JOIN users u ON o.user_id = u.id;

Solution 4: Run in Background

SQL

-- For long-running queries, consider background processing
-- Using pg_cron or external job queue

Solution 5: Increase Application Timeout

JAVASCRIPT

// Node.js with pg
const client = new Client({
  statement_timeout: 60000,  // 60 seconds
});

// Or per query
await client.query('SET statement_timeout = 60000');

Solution 6: Use COPY for Bulk Operations

SQL

-- Instead of many INSERTs
COPY large_table FROM '/path/to/file.csv' WITH CSV HEADER;

Checking Current Timeout

SQL

SHOW statement_timeout;
SHOW lock_timeout;
SHOW idle_in_transaction_session_timeout;

Best Practices

Set appropriate timeouts for your workload
Optimize slow queries instead of just increasing timeouts
Use connection pooling with proper timeout settings
Monitor query performance regularly
Consider async processing for long operations