diff --git a/website/docs/reference/resource-configs/snowflake-configs.md b/website/docs/reference/resource-configs/snowflake-configs.md index 30c7966ec68..aa2bf370df6 100644 --- a/website/docs/reference/resource-configs/snowflake-configs.md +++ b/website/docs/reference/resource-configs/snowflake-configs.md @@ -346,82 +346,122 @@ In the configuration format for the model SQL file: ## Dynamic tables -The Snowflake adapter supports [dynamic tables](https://docs.snowflake.com/en/sql-reference/sql/create-dynamic-table). +The Snowflake adapter supports [dynamic tables](https://docs.snowflake.com/en/user-guide/dynamic-tables-about). This materialization is specific to Snowflake, which means that any model configuration that would normally come along for the ride from `dbt-core` (e.g. as with a `view`) may not be available for dynamic tables. This gap will decrease in future patches and versions. While this materialization is specific to Snowflake, it very much follows the implementation of [materialized views](/docs/build/materializations#Materialized-View). In particular, dynamic tables have access to the `on_configuration_change` setting. -There are also some limitations that we hope to address in the next version. +Dynamic tables are supported with the following configuration parameters: -### Parameters +| Parameter | Type | Required | Default | Change Monitoring Support | +|----------------------------------------------------------|------------|----------|---------|---------------------------| +| `on_configuration_change` | `` | no | `apply` | n/a | +| [`target_lag`](#target-lag) | `` | yes | | alter | +| [`snowflake_warehouse`](#configuring-virtual-warehouses) | `` | yes | | alter | -Dynamic tables in `dbt-snowflake` require the following parameters: -- `target_lag` -- `snowflake_warehouse` -- `on_configuration_change` + -To learn more about each parameter and what values it can take, see -the Snowflake docs page: [`CREATE DYNAMIC TABLE: Parameters`](https://docs.snowflake.com/en/sql-reference/sql/create-dynamic-table). -### Usage + -You can create a dynamic table by editing _one_ of these files: + -- the SQL file for your model -- the `dbt_project.yml` configuration file +```yaml +models: + [](/reference/resource-configs/resource-path): + [+](/reference/resource-configs/plus-prefix)[materialized](/reference/resource-configs/materialized): dynamic_table + [+](/reference/resource-configs/plus-prefix)on_configuration_change: apply | continue | fail + [+](/reference/resource-configs/plus-prefix)[target_lag](#target-lag): downstream | + [+](/reference/resource-configs/plus-prefix)[snowflake_warehouse](#configuring-virtual-warehouses): +``` -The following examples create a dynamic table: + - + -```sql -{{ config( - materialized = 'dynamic_table', - snowflake_warehouse = 'snowflake_warehouse', - target_lag = '10 minutes', -) }} -``` - + - + ```yaml +version: 2 + models: - path: - materialized: dynamic_table - snowflake_warehouse: snowflake_warehouse - target_lag: '10 minutes' + - name: [] + config: + [materialized](/reference/resource-configs/materialized): dynamic_table + on_configuration_change: apply | continue | fail + [target_lag](#target-lag): downstream | + [snowflake_warehouse](#configuring-virtual-warehouses): ``` -### Monitored configuration changes + -The settings below are monitored for changes applicable to `on_configuration_change`. -#### Target lag + -Changes to `target_lag` can be applied by running an `ALTER` statement. Refreshing is essentially -always on for dynamic tables; this setting changes how frequently the dynamic table is updated. + -#### Warehouse +```jinja +{{ config( + [materialized](/reference/resource-configs/materialized)="dynamic_table", + on_configuration_change="apply" | "continue" | "fail", + [target_lag](#target-lag)="downstream" | " seconds | minutes | hours | days", + [snowflake_warehouse](#configuring-virtual-warehouses)="", +) }} +``` + + + + + + + +Find more information about these parameters in Snowflake's [docs](https://docs.snowflake.com/en/sql-reference/sql/create-dynamic-table): -Changes to `snowflake_warehouse` can be applied via an `ALTER` statement. +### Target lag + +Snowflake allows two configuration scenarios for scheduling automatic refreshes: +- **Time-based** — Provide a value of the form ` { seconds | minutes | hours | days }`. For example, if the dynamic table needs to be updated every 30 minutes, use `target_lag='30 minutes'`. +- **Downstream** — Applicable when the dynamic table is referenced by other dynamic tables. In this scenario, `target_lag='downstream'` allows for refreshes to be controlled at the target, instead of at each layer. + +Find more information about `target_lag` in Snowflake's [docs](https://docs.snowflake.com/en/user-guide/dynamic-tables-refresh#understanding-target-lag). ### Limitations +As with materialized views on most data platforms, there are limitations associated with dynamic tables. Some worth noting include: + +- Dynamic table SQL has a [limited feature set](https://docs.snowflake.com/en/user-guide/dynamic-tables-tasks-create#query-constructs-not-currently-supported-in-dynamic-tables). +- Dynamic table SQL cannot be updated; the dynamic table must go through a `--full-refresh` (DROP/CREATE). +- Dynamic tables cannot be downstream from: materialized views, external tables, streams. +- Dynamic tables cannot reference a view that is downstream from another dynamic table. + +Find more information about dynamic table limitations in Snowflake's [docs](https://docs.snowflake.com/en/user-guide/dynamic-tables-tasks-create#dynamic-table-limitations-and-supported-functions). + + + #### Changing materialization to and from "dynamic_table" -Swapping an already materialized model to be a dynamic table and vice versa. -The workaround is manually dropping the existing materialization in the data warehouse prior to calling `dbt run`. -Normally, re-running with the `--full-refresh` flag would resolve this, but not in this case. -This would only need to be done once as the existing object would then be a dynamic table. +Version `1.6.x` does not support altering the materialization from a non-dynamic table be a dynamic table and vice versa. +Re-running with the `--full-refresh` does not resolve this either. +The workaround is manually dropping the existing model in the warehouse prior to calling `dbt run`. +This only needs to be done once for the conversion. For example, assume for the example model below, `my_model`, has already been materialized to the underlying data platform via `dbt run`. -If the user changes the model's config to `materialized="dynamic_table"`, they will get an error. +If the model config is updated to `materialized="dynamic_table"`, dbt will return an error. The workaround is to execute `DROP TABLE my_model` on the data warehouse before trying the model again. @@ -429,7 +469,7 @@ The workaround is to execute `DROP TABLE my_model` on the data warehouse before ```yaml {{ config( - materialized="table" # or any model type eg view, incremental + materialized="table" # or any model type (e.g. view, incremental) ) }} ``` @@ -437,3 +477,5 @@ The workaround is to execute `DROP TABLE my_model` on the data warehouse before + +