# Migration Tools Decision Summary - Goose vs Atlas

## The Question: "Why not Atlas or others?"

You asked about Atlas and other migration tools. Here's the comprehensive answer.

## TL;DR Answer

**Use Goose for TraceRTM because:**
- ✅ Simple (5 min setup vs 15 min for Atlas)
- ✅ Embedded migrations (compile into binary)
- ✅ Works perfectly with pgx
- ✅ Large community
- ✅ Production-proven
- ✅ No external dependencies

**Consider Atlas later if:**
- You want auto-generated migrations
- Schema becomes complex
- You need schema drift detection

## The Two Main Approaches

### Goose: Versioned Migrations (Traditional)
```sql
-- +goose Up
CREATE TABLE users (id UUID PRIMARY KEY);

-- +goose Down
DROP TABLE users;
```
- Manual SQL writing
- Tracks which migrations ran
- Apply in order
- Rollback if needed

### Atlas: Schema-as-Code (Declarative)
```hcl
table "users" {
  column "id" {
    type = uuid
    primary_key = true
  }
}
```
- Define schema in HCL
- Auto-generates migrations
- Detects schema drift
- More powerful but complex

## Quick Comparison

| Feature | Goose | Atlas |
|---------|-------|-------|
| **Setup Time** | 5 min | 15 min |
| **Learning Curve** | Easy | Medium |
| **Embedded** | ✅ | ❌ |
| **Auto-Generate** | ❌ | ✅ |
| **Community** | Large | Growing |
| **Maturity** | Proven | Newer |
| **pgx Integration** | Perfect | Good |

## Why Goose Wins for TraceRTM

### 1. Simplicity
- Easy to understand
- Traditional approach
- Familiar to most developers

### 2. Embedded Migrations
- Compile migrations into binary
- Single binary deployment
- Perfect for containerization

### 3. pgx Integration
- Direct integration
- No abstraction layer
- Type-safe

### 4. Community
- Large community
- Lots of help available
- Production-proven

### 5. Production-Proven
- Used in many projects
- Stable and mature
- No API changes expected

### 6. No Dependencies
- Keep stack pure Go
- Minimal overhead
- Easy to maintain

## Why Not Atlas (For Now)

### 1. Steeper Learning Curve
- HCL syntax to learn
- Different mental model
- More configuration

### 2. No Embedded Migrations
- CLI-only approach
- Can't compile into binary
- More complex deployment

### 3. Smaller Community
- Less Stack Overflow help
- Fewer examples
- Newer tool (started 2022)

### 4. Overkill for TraceRTM
- Schema is not that complex
- Auto-generation not needed
- Overhead not justified

### 5. Less Mature
- Fewer production deployments
- Potential bugs
- API changes possible

## When to Use Atlas

✅ **Use Atlas if:**
- You want auto-generated migrations
- Schema becomes complex
- You need schema drift detection
- You're using Ent ORM
- You want declarative schema

❌ **Don't use Atlas if:**
- You prefer manual control
- You need embedded migrations
- You want simplicity
- You have simple schema

## Migration Path: Goose → Atlas

If you start with Goose and want to migrate to Atlas later:

```bash
# 1. Export current schema
atlas schema inspect -u "postgresql://..." --format hcl > schema.hcl

# 2. Create schema.hcl
# Edit schema.hcl to match your schema

# 3. Generate migrations with Atlas
atlas migrate diff --env local

# 4. Switch to Atlas
atlas migrate apply --env prod
```

Both tools work with PostgreSQL, so migration is possible!

## Other Tools Considered

### golang-migrate
- ✅ Lightweight
- ✅ Multiple sources (file, GitHub, S3, GCS)
- ❌ SQL-only (no Go migrations)
- ❌ Smaller community

### Alembic
- ✅ Auto-generates migrations
- ✅ Powerful (complex logic)
- ❌ Python-based (not Go)
- ❌ Separate from Go codebase

### dbmate
- ✅ Very simple
- ✅ Docker-friendly
- ❌ Very basic
- ❌ Small community

## Decision Matrix

```
Simple project?
├─ YES → Use Goose ✅
└─ NO → Need auto-generation?
    ├─ YES → Use Atlas
    └─ NO → Use Goose ✅
```

## Recommendation

**For TraceRTM: START WITH GOOSE**

Reasons:
- ✅ Simple to implement (5 minutes)
- ✅ Works perfectly with pgx
- ✅ Embedded migrations support
- ✅ Large community
- ✅ Production-proven
- ✅ No external dependencies

**Consider Atlas Later If:**
- ✅ You want auto-generated migrations
- ✅ Schema becomes complex
- ✅ You need schema drift detection
- ✅ You're using Ent ORM
- ✅ You want declarative schema

## Documentation Files

### For Understanding the Decision
- **WHY_GOOSE_NOT_ATLAS.md** - Detailed explanation
- **MIGRATION_TOOLS_DETAILED_COMPARISON.md** - All tools compared

### For Atlas Alternative
- **ATLAS_ALTERNATIVE_GUIDE.md** - If you want to know more

### For Implementation
- **GO_MIGRATIONS_GUIDE.md** - Quick start
- **GOOSE_IMPLEMENTATION_GUIDE.md** - Step-by-step
- **MIGRATIONS_SUMMARY.md** - Quick reference

## Next Steps

1. Read WHY_GOOSE_NOT_ATLAS.md
2. Read MIGRATION_TOOLS_DETAILED_COMPARISON.md
3. Read GO_MIGRATIONS_GUIDE.md
4. Install Goose
5. Create migrations directory
6. Create first migration
7. Test locally
8. Integrate with main.go
9. Deploy to Supabase

## Conclusion

**Goose is the right choice for TraceRTM because:**
- Simple to implement
- Works perfectly with pgx
- Embedded migrations support
- Large community
- Production-proven
- No external dependencies

**You can always migrate to Atlas later if needed.**

Both tools work with PostgreSQL, so migration is possible without losing data.

**Ready to implement? Start with GO_MIGRATIONS_GUIDE.md!**

