Warehouse Configuration Rules

This rule applies to files matching the patterns above.

# Warehouse Configuration Rules

## Rule
All Snowflake warehouses MUST have auto-suspend configured, resource monitors attached, and be sized appropriately for their workload type.

## Required Configuration
```sql
CREATE WAREHOUSE etl_wh WITH
  WAREHOUSE_SIZE = 'SMALL'
  AUTO_SUSPEND = 300            -- REQUIRED: seconds (60-3600)
  AUTO_RESUME = TRUE            -- REQUIRED
  MIN_CLUSTER_COUNT = 1
  MAX_CLUSTER_COUNT = 3         -- For multi-cluster
  SCALING_POLICY = 'ECONOMY'    -- For batch workloads
  INITIALLY_SUSPENDED = TRUE
  COMMENT = 'ETL pipeline processing. Owner: data-engineering.';
```

## Warehouse Separation (Required)
```sql
-- Separate warehouses by workload type
-- Good
CREATE WAREHOUSE etl_wh ...;        -- Data engineering
CREATE WAREHOUSE analytics_wh ...;  -- BI and reporting
CREATE WAREHOUSE ds_wh ...;         -- Data science
CREATE WAREHOUSE dev_wh ...;        -- Development/testing

-- Bad — one warehouse for everything
CREATE WAREHOUSE my_warehouse ...;  -- ETL + BI + DS mixed
```

## Auto-Suspend Rules
| Workload | Auto-Suspend | Why |
|----------|-------------|-----|
| Interactive BI | 60 seconds | Quick resume, frequent use |
| ETL/ELT | 300 seconds | Avoid resume between tasks |
| Data Science | 300 seconds | Long intervals between queries |
| Dev/Test | 60 seconds | Minimize idle costs |

## Resource Monitors (Required)
```sql
-- Every warehouse must have a resource monitor
CREATE RESOURCE MONITOR etl_monitor WITH
  CREDIT_QUOTA = 500
  FREQUENCY = MONTHLY
  START_TIMESTAMP = IMMEDIATELY
  TRIGGERS
    ON 75 PERCENT DO NOTIFY
    ON 90 PERCENT DO NOTIFY
    ON 100 PERCENT DO SUSPEND;

ALTER WAREHOUSE etl_wh SET RESOURCE_MONITOR = etl_monitor;
```

## Sizing Guidelines
```
Rule: Start XSMALL, scale up only when queries are consistently slow
Rule: Double size = 2x compute, 2x cost, but NOT always 2x faster
Rule: Wide queries (many rows, few columns) benefit from larger size
Rule: Deep queries (many joins, complex logic) may not benefit from scaling up
```

## Good Configuration
```sql
-- Dedicated, right-sized, monitored
CREATE WAREHOUSE analytics_wh WITH
  WAREHOUSE_SIZE = 'XSMALL'
  AUTO_SUSPEND = 60
  AUTO_RESUME = TRUE
  SCALING_POLICY = 'STANDARD'
  COMMENT = 'BI dashboard queries. Owner: analytics.';
```

## Bad Configuration
```sql
-- Oversized, no suspend, no monitor
CREATE WAREHOUSE my_wh WITH
  WAREHOUSE_SIZE = 'XLARGE'     -- Start small!
  AUTO_SUSPEND = 0              -- Never suspends! Burns credits 24/7
  -- No COMMENT, no resource monitor
```

## Anti-Patterns
- AUTO_SUSPEND = 0 (warehouse never suspends, burns credits)
- No resource monitor (surprise bills)
- Starting with LARGE+ size (wasteful, start XSMALL)
- One warehouse for all workloads (can't optimize individually)
- Missing COMMENT (nobody knows the warehouse's purpose)