Write a query to find the month-over-month growth rate of active Smart TV users in a specific region for Samsung Ads.
Use the region Seoul, count distinct active Smart TV users by calendar month, and calculate growth relative to the previous month. Return all available months for that region, including the first month with no prior-month comparison.
month, active_users, previous_month_active_users, and growth_rate.growth_rate as a decimal ratio rounded to four decimal places, or NULL when no prior month exists.| Column | Type | Description |
|---|---|---|
| activity_idPK | INT | Unique activity record identifier |
| user_id | INT | Identifier of the Smart TV user |
| region_id | INT | Region associated with the activity |
| activity_date | DATE | Date of the recorded activity |
| device_type | VARCHAR(50) | Device category used for the activity |
| is_active | BOOLEAN | Whether the activity qualifies as active usage |
| Column | Type | Description |
|---|---|---|
| region_idPK | INT | Unique region identifier |
| region_name | VARCHAR(100) | Samsung Ads reporting region name |