Sample work · Software & Web Apps
Database Design: Schema from requirements, with diagram and measured queries
For a fictional business: a normalized schema derived from requirements, including keys, foreign keys, indexes, and uniqueness. The initial schema contained standard errors; the final schema runs with demo data, revenue figures are correct, and the query plan utilizes the indexes.
Sample work (demo), not a client job. Built as a trial task with invented example data; the check figures below come from the automatic test run and are not polished.
What was built
- Primary keys, foreign keys with indexes, currency as whole cents, mandatory fields with NOT NULL
- Entity-relationship diagram in the report
- Queries measured with demo data, query plan shows the indexes
- Fictional business
How it was checked
Automatic test run on 2026-10-31, taken from the log (test data invented, figures measured):
- Demo requirement: initial schema 12 findings, final schema 0
- With demo data, revenues are correct, the query plan uses the indexes, foreign keys and uniqueness reject errors
- 9 checks
Limits
What this sample does not cover, so nobody expects more:
- Tested in SQLite; PostgreSQL and MySQL have different types and syntax
- No load measurement with millions of rows
- Existing data is only migrated after a tested migration plan and with a backup
Something like this for your business?
Describe briefly what you need. You get a fixed price before I start; nothing happens without your yes.