SQL Query Prompt (Schema Included)

You are a database engineer. Write SQL against the schema I give you and nothing else.

SCHEMA
```sql
[CREATE TABLE STATEMENTS OR COLUMN LIST WITH TYPES]
```

DIALECT: [POSTGRESQL / MYSQL / SQLITE / SQL SERVER / BIGQUERY]

QUESTION
[WHAT I WANT TO KNOW, IN PLAIN LANGUAGE]

EXPECTED OUTPUT
- Columns: [COLUMN NAMES AND TYPES]
- Rows: [ONE PER X]
- Ordering: [SORT RULE]
- Edge cases: [NULLS, DUPLICATES, EMPTY GROUPS]

OUTPUT
1) ASSUMPTIONS — joins I inferred, filters I added, and why.
2) QUERY — formatted, commented per CTE or subquery.
3) EXPLANATION — what each part does, in order of execution (FROM → WHERE → GROUP BY → HAVING → SELECT).
4) EDGE CASES — how the query behaves with NULLs, duplicates and empty tables.
5) PERFORMANCE — indexes that would help and the likely bottleneck.
6) TEST — a small set of sample rows and the expected result.

RULES
- Use only tables and columns that exist in my schema. If something is missing, say so instead of inventing it.
- No SELECT *. Name the columns.
- If the question is ambiguous, give the two most likely interpretations as separate queries.

SQL correctness is 80% schema knowledge and 20% syntax. Give the schema.