snowflake-reliability-patterns

# Snowflake Reliability Patterns ## Overview Production-grade reliability patterns for Snowflake: database replication, account failover, Time Travel recovery, and application-level circuit breakers. ## Instructions ### Step 1: Time Travel for Point-in-Time Recovery ```sql -- Query historical data (up to 90 days on Enterprise Edition) SELECT * FROM orders AT (TIMESTAMP => '2026-03-21 14:00:00'::TIMESTAMP_NTZ); -- Restore a table to a previous state CREATE OR REPLACE TABLE orders CLONE orders AT (TIMESTAMP => '2026-03-21 14:00:00'::TIMESTAMP_NTZ); -- Restore a dropped table UNDROP TABLE orders; UNDROP SCHEMA my_schema; UNDROP DATABASE my_database; -- Query by offset (5 minutes ago) SELECT * FROM orders AT (OFFSET => -300); -- Query by statement ID (before a specific query ran) SELECT * FROM orders BEFORE (STATEMENT => '<query_id_of_bad_update>'); -- Set retention period per table ALTER TABLE critical_data SET DATA_RETENTION_TIME_IN_DAYS = 90; ALTER TABLE temp_staging SET DATA_RETENTION_TIME_IN_DAYS = 0; -- No Time Travel ``` ### Step 2: Database Replication Across Regions ```sql -- Enable replication on source account (primary) ALTER DATABASE PROD_DW ENABLE REPLICATION TO ACCOUNTS myorg.us_east_account, myorg.eu_west_account; -- On target account: create replica database CREATE DATABASE PROD_DW_REPLICA AS REPLICA OF myorg.us_west_account.PROD_DW; -- Refresh replica (manual or scheduled) ALTER DATABASE PROD_DW_REPLICA REFRESH; -- Check replication status...