Add: Schema-qualified table names in Bruin

Closes #214

Author: github-actions[bot]

_questions/data-engineering-zoomcamp/module-5/005_8ef4012c69_schema-qualified-downstream-tables-bruin.md

@@ -0,0 +1,27 @@
+---
+id: 8ef4012c69
+question: Why do downstream Bruin assets fail with 'Table does not exist' error even
+  though the upstream ingestion asset succeeded?
+sort_order: 5
+---
+
+Bruin creates tables inside schemas (for example ingestion, staging, reports). If you reference a table without its schema, DuckDB will not find it and will raise a “Table does not exist” error, even if the upstream ingestion asset ran successfully. Always use schema-qualified names in downstream assets. You can verify existing tables with:
+
+```bash
+bruin query -c duckdb-default -q "SELECT table_schema, table_name FROM information_schema.tables;"
+```
+
+Example of the pitfall and the fix:
+
+```
+-- This will fail if the table was created as ingestion.trips_raw
+SELECT * FROM trips_raw;
+
+-- Correct:
+SELECT * FROM ingestion.trips_raw;
+```
+
+Notes:
+- Always reference the fully-qualified table name that the upstream asset created (e.g., ingestion.trips_raw, staging.orders, reports.sales_summary).
+- If you’re unsure which schema a table lives in, list tables with the command above and inspect the schema column.
+- Consider using explicit schema qualification in all downstream assets to prevent these errors.