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distribution

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Usage

view: my_view {
  derived_table: {
    distribution: "customer_id"
    …
  }
}

Hierarchy

view
derived_table
distribution

- or -

explore
aggregate_table
materialization
distribution

Default Value

None

Accepts

The name of a column in a derived table or aggregate table

Special Rules

distribution is supported only for Redshift and Aster databases.

Definition

distribution lets you specify the column from a persistent derived table (PDT) or an aggregate table on which to apply a distribution key. Currently, distribution works only with Redshift and Aster databases. For other SQL dialects (such as MySQL and Postgres), use indexes instead.

The distribution parameter works only with tables that are persistent, such as PDTs and aggregate tables. distribution is not supported for derived tables without a persistence strategy.

In addition, the distribution parameter is not supported for derived tables that are defined using create_process or sql_create.

Generally speaking, a distribution key should be applied to the column that will be acting as a foreign key (the column you use to join your table to others). Refer to the documentation for your dialect for best practices.

Examples

Create a customer_order_facts persistent derived table with a distribution key on customer_id:

view: customer_order_facts { derived_table: { explore_source: order { column: customer_id { field: order.customer_id } column: lifetime_orders { field: order.lifetime_orders } } datagroup_trigger: order_datagroup distribution: "customer_id" } }

Create a customer_order_facts derived table based on a SQL query with a distribution key on customer_id:

view: customer_order_facts { derived_table: { sql: SELECT customer_id, COUNT(*) AS lifetime_orders FROM order ;; persist_for: "24 hours" distribution: "customer_id" } }