dbt-transformation-patterns

# dbt Transformation Patterns Production-ready patterns for dbt (data build tool) including model organization, testing strategies, documentation, and incremental processing. ## When to Use This Skill - Building data transformation pipelines with dbt - Organizing models into staging, intermediate, and marts layers - Implementing data quality tests - Creating incremental models for large datasets - Documenting data models and lineage - Setting up dbt project structure ## Core Concepts ### 1. Model Layers (Medallion Architecture) ``` sources/ Raw data definitions ↓ staging/ 1:1 with source, light cleaning ↓ intermediate/ Business logic, joins, aggregations ↓ marts/ Final analytics tables ``` ### 2. Naming Conventions | Layer | Prefix | Example | | ------------ | -------------- | ----------------------------- | | Staging | `stg_` | `stg_stripe__payments` | | Intermediate | `int_` | `int_payments_pivoted` | | Marts | `dim_`, `fct_` | `dim_customers`, `fct_orders` | ## Quick Start ```yaml # dbt_project.yml name: "analytics" version: "1.0.0" profile: "analytics" model-paths: ["models"] analysis-paths: ["analyses"] test-paths: ["tests"] seed-paths: ["seeds"] macro-paths: ["macros"] vars: start_date: "2020-01-01" models: analytics: staging: +materialized: view +schema: staging intermediate: +materialized: ephemeral marts: +materialized: table +schema: analytics ``` ``` # Project structure models/ ├── staging/ │ ├── stripe/ │ │ ├── _stripe__sources.yml │ │ ├── _stripe__models.yml │ │ ├── stg_stripe__customers.sql │ │ └── stg_stripe__payments.sql │ └── shopify/ │ ├── _shopify__sources.yml │ └── stg_shopify__orders.sql ├── intermediate/ │ └── finance/ │ └── int_payments_pivoted.sql └── marts/ ├── core/ │ ├── _core__models.yml │ ├── dim_customers.sql │ └── fct_orders.sql └── finance/ └── fct_revenue.sql ``` ## Detailed patterns and worked examples Detailed pattern documentation lives in `references/details.md`. Read that file when the navigation tier above is insufficient. ## Best Practices ### Do's - **Use staging layer** - Clean data once, use everywhere - **Test aggressively** - Not null, unique, relationships - **Document everything** - Column descriptions, model descriptions - **Use incremental** - For tables > 1M rows - **Version control** - dbt project in Git ### Don'ts - **Don't skip staging** - Raw → mart is tech debt - **Don't hardcode dates** - Use `{{ var('start_date') }}` - **Don't repeat logic** - Extract to macros - **Don't test in prod** - Use dev target - **Don't ignore freshness** - Monitor source data