The tables in the target database contain existing data. By default, the subsetter requires empty target tables to prevent accidental data loss.

How to fix

Choose one of these approaches:

Option 1: Clear target database manually

1. Backup your target database (if needed)
2. Delete existing data from target tables
3. Re-run the subsetter with empty tables

Option 2: Use overwrite mode

Run the subsetter with the overwrite flag:

rgsubset run --target-database-write-mode overwrite [other options]

Understanding write modes

Strict (default): Fails if target tables contain data - prevents accidental overwrites

Overwrite: Automatically deletes existing data before subsetting - use with caution

When to use overwrite mode 

Development environments: Safe to replace test data

Iterative subsetting: Running multiple subset operations on the same target

Known empty requirement: When you're certain existing data should be replaced