View​ Materialization

A view materialization is dbt's default method for creating models. Instead of storing data physically like a table, a view is a saved SQL query that executes each time you access it. This means:

• Views always show the latest source data

• No additional storage is required

• The transformation logic runs on every query

If you don't specify a materialization, dbt will create your model as a view by default.

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Working with Views

Let's understand views through a simple example:

-- models/staging/stg_orders.sql
SELECT 
    order_id,
    customer_id,
    order_date
FROM {{ ref('raw_orders') }}

When someone queries this view:

1. The warehouse executes the underlying SQL

2. Results reflect the current data in raw_orders

3. No data is stored permanently

Under the hood, dbt™ executes a CREATE VIEW or CREATE OR REPLACE VIEW statement:

CREATE OR REPLACE VIEW "database"."schema"."my_view" AS (
    SELECT * FROM source_table WHERE condition = true
);

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When to Use Views

Views are ideal for:

• Simple transformations (renaming columns, basic calculations)

• Staging models that clean and prepare source data

• Development and testing before optimization

• Real-time data requirements

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Configuration

Views can be configured in your model files or project configuration.

Model-Level Configuration

-- In your model SQL file
{{
  config(
    materialized='view'
  )
}}

SELECT 
    order_id,
    customer_name,
    order_date,
    order_amount,
    status
FROM {{ ref('raw_orders') }}
WHERE order_date >= '2024-01-01'

Project-Level Configuration

# In your dbt_project.yml file
models:
  your_project:
    staging:
      +materialized: view

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Performance and Usage Guidelines

Advantages and Limitations

Advantages	Limitations
🔄 Always reflects current source data	🐌 Can be slow for complex transformations
💰 No storage costs	🏋️ Resource-intensive for frequent queries
🛠️ Easy to modify and test	⚠️ Not ideal for nested views
🎯 Simple to maintain

When to Change Materialization

Consider changing from a view when you encounter:

• Slow query performance

• High computation costs

• Frequent access patterns

• Complex transformations

Best Practices

1. Start with Views: Begin with views and change only when needed

2. Monitor Performance: Track query times and resource usage

3. Optimize Strategically: Limit nesting, use tables for complex analytics

Views are ideal for development and simple transformations. Switch to other materializations only when performance requirements demand it.