Chain Snowflake dynamic tables into a DAG using target_lag propagation

Steps

1. Create each dynamic table with CREATE DYNAMIC TABLE ... TARGET_LAG = '<n> seconds|minutes|hours|days' WAREHOUSE = <wh> AS <query>, or TARGET_LAG = DOWNSTREAM to opt out of an independent schedule.
2. For a DOWNSTREAM table, know that Snowflake refreshes it only as needed to satisfy the shortest target_lag among the tables that consume it — it has no schedule of its own.
3. Verify every terminal (leaf) table in the DAG uses an explicit numeric target_lag, not DOWNSTREAM, since a DOWNSTREAM table with no consumer never auto-refreshes and Snowflake gives no warning.
4. Leave REFRESH_MODE = AUTO (the default) unless you have a reason to force FULL or INCREMENTAL — AUTO resolves once at creation and is locked in, not re-evaluated as the query changes.
5. Check which mode was actually chosen with SHOW DYNAMIC TABLES and inspect the refresh_mode / refresh_mode_reason columns.
6. To change a locked-in refresh mode, CREATE OR REPLACE (or CREATE OR ALTER) the dynamic table — ALTER DYNAMIC TABLE cannot change it directly.