> ## Documentation Index
> Fetch the complete documentation index at: https://www.propeldata.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Advanced examples

> Advanced Terraform examples for Propel resources

<div />

This page provides advanced examples that demonstrate more complex scenarios and configurations that go beyond basic resource creation.

## Example 1: Creating a Materialized View with a source Data Pool with an access policy

This example shows how to create a Materialized View with a source Data Pool that has an access policy.

<Steps>
  <Step title="Create the source Data Pool">
    First, we create the source Data Pool with access control enabled. This is done using the `propel_data_pool` resource.

    ```hcl theme={"system"}
    resource "propel_data_pool" "my_data_pool" {
      unique_name = "My Data Pool"
      description = "This is an example of a Data Pool"
      timestamp   = "date"

      access_control_enabled = true

      column {
        name     = "date"
        type     = "TIMESTAMP"
        nullable = false
      }
      column {
        name     = "account_id"
        type     = "STRING"
        nullable = false
      }
    }
    ```
  </Step>

  <Step title="Create the access policy">
    Next, we create the access policy for the source Data Pool. This policy gives access to the Terraform application and any other Applications that you specify. We use the `propel_data_pool_access_policy` resource for this.

    ```hcl theme={"system"}
    resource "propel_data_pool_access_policy" "my_terraform_policy" {
      unique_name = "Data Pool Access Policy"
      data_pool = propel_data_pool.my_data_pool.id

      columns = ["*"]
      applications = [ var.terraform_application_id ]
    }
    ```
  </Step>

  <Step title="Create the Materialized View">
    Finally, we create the Materialized View. The challenge here is that the policy needs to be created before the Materialized View queries, otherwise it will not have access to the data. To avoid this, we use the Data Pool ID from the Data Pool Access Policy `${propel_data_pool_access_policy.my_terraform_policy.data_pool}` so that Terraform will wait for the policy to be created before the Materialized View is created.

    ```hcl theme={"system"}
    resource "propel_materialized_view" "my_materialized_view" {
      unique_name = "My Materialized View"
      sql = <<-SQL
        SELECT
          *
        FROM ${propel_data_pool_access_policy.my_terraform_policy.data_pool}
      SQL
    }
    ```
  </Step>
</Steps>