Turso Alpha Database Testing - AI-Optimized Reference

Current Status (September 2025)

• Version State: Rapidly changing releases, nightly builds with unpredictable stability
• Maturity Level: Experimental alpha with known data corruption risks
• MVCC Feature: Experimental, guaranteed to corrupt test data in current state

Critical Failure Modes

Database Corruption

• Trigger: Using MVCC mode with normal transactions
• Impact: Complete database file corruption, unrecoverable data
• Frequency: High (documented multiple corruptions during testing)
• Fix: Restore from backup, use WAL mode instead of MVCC
• Command: PRAGMA integrity_check before any testing

Connection Lock Issues

• Trigger: ROLLBACK operations in MVCC mode
• Issue: #3064 - locks not released after rollbacks
• Impact: Database permanently locked, connection unusable
• Fix: Kill connection and create new one, avoid connection reuse after failures

DELETE Operations Failure

• Issue: #3062 - DELETE statements don't remove rows in MVCC
• Impact: Data integrity violations, ghost records persist
• Workaround: Verify deletions with SELECT COUNT(*), avoid MVCC entirely

Index Crashes

• Issue: #3052 - panic on index seeks with BEGIN CONCURRENT
• Impact: Application crashes during concurrent operations
• Fix: Disable indexes or avoid concurrent transactions

Platform-Specific Issues

Apple Silicon (M1/M2 Macs)

• Problem: x64 build segmentation faults on ARM processors
• Fix: Use ARM-specific download
• Command: curl -L https://github.com/tursodatabase/turso/releases/latest/download/turso_cli-aarch64-apple-darwin.tar.xz

Linux GLIBC Dependencies

• Requirement: glibc 2.29+ (Ubuntu 20.04+)
• Failure: "GLIBC_2.29 not found" on Ubuntu 18.04
• Fix: Upgrade OS or use Docker approach

Node.js Memory Leaks

• Trigger: 50+ concurrent queries
• Impact: Memory leaks leading to crashes
• Mitigation: Limit to 10 concurrent connections, implement retry logic

Language Binding Failures

JavaScript/WASM

• Memory Bug: Random ConnectionError exceptions under load
• Fix: Connection pooling with max 10 connections
• Code: const pool = new Pool({ max: 10 });

Go Driver

• Issue: Sync API race conditions causing panics
• Fix: Use async API with retry logic

Python asyncio

• Problem: Infinite hangs on await operations
• Fix: Wrap with timeout: await asyncio.wait_for(db.execute(query), timeout=30.0)

Windows Support

• Status: Experimental, io_uring doesn't work
• Recommendation: Use WSL2 or Linux for testing

Performance Characteristics

Working Well

• Basic CRUD operations: Sub-50ms response times
• Async I/O improvements: Handles 1000 SELECT statements effectively
• Vector search: Functional when not using experimental features

Performance Issues

• Complex JOINs: Randomly slower than SQLite
• Schema operations: 4GB+ memory usage with 500+ tables
• WAL checkpointing: Insufficient in alpha, requires manual intervention

Testing Strategy by Risk Level

Approach	Duration	Data Safety	Use Case
Production Clone	2-3 weeks	High	Migration feasibility
Feature-by-Feature	4-6 weeks	Medium	Reliability assessment
Load Testing	1-2 weeks	Low	Breaking point discovery
MVCC Stress	Ongoing	Very Low	Development contribution

Essential Configuration

Safe Testing Setup

-- Avoid experimental features
PRAGMA journal_mode=WAL;  -- NOT MVCC
PRAGMA foreign_keys=OFF;  -- During import
PRAGMA integrity_check;   -- Before any testing

Connection Retry Pattern

async fn connect_with_retry(path: &str, max_attempts: u32) -> Result<Connection> {
    let mut attempts = 0;
    loop {
        match turso::connect(path).await {
            Ok(conn) => return Ok(conn),
            Err(e) if attempts < max_attempts => {
                attempts += 1;
                tokio::time::sleep(Duration::from_millis(100 * attempts as u64)).await;
            }
            Err(e) => return Err(e),
        }
    }
}

Critical Backup Procedures

• Before testing: cp production.db backup-$(date +%Y%m%d-%H%M%S).db
• After schema changes: turso-cli .dump | gzip > backup-schema-$(date +%Y%m%d).sql.gz
• Integrity verification: Run PRAGMA integrity_check after risky operations

Debugging Toolkit

Connection Issues

lsof -p $(pgrep turso) | grep db  # Open file handles

WAL Problems

file database.db-wal          # Verify WAL file type
wc -c database.db-wal         # Size check (>100MB indicates checkpoint issues)

Memory Leaks

ps aux | grep turso           # Memory usage (>2GB indicates leaks)

Error Analysis

grep -E "(panic|SIGABRT|corruption)" /var/log/turso.log

Resource Requirements

Time Investment

• Expected: 2 weeks testing
• Reality: 6 weeks with debugging
• Breakdown: Weeks 1-2 basic functionality, 3-4 edge cases, 5-6 deep debugging

Memory Requirements

• Normal operations: <1GB
• Schema migrations: 4GB+ for large schemas
• Docker containers: Increase memory limits to prevent OOMKill (exit code 137)

Expertise Requirements

• Database debugging: Essential for alpha testing
• Connection pooling: Required for stable applications
• Backup/recovery procedures: Critical for data safety

Support Resources

• GitHub Issues: Primary bug tracking
• Discord Server: Real-time maintainer support
• Latest Releases: Version tracking
• Response time: Fast for detailed bug reports with crash logs

Migration Decision Criteria

Skip Turso If

• Production stability required
• MVCC features needed immediately
• Windows-only deployment
• Cannot tolerate data corruption risk

Consider Turso If

• Testing experimental SQLite features
• Contributing to open source development
• Evaluating future migration possibilities
• Have robust backup/recovery procedures

Alternative Solutions

• DuckDB: For read-heavy analytical workloads
• Standard SQLite: For production stability
• PostgreSQL: For mature concurrent write support