Mode disclosure
All modes use one coherent workspace; only disclosure and guidance change. Project mode keeps the persistent brief, milestones, notes, saved intermediate queries, validation checklist, and report export together.
Northstar Commerce Executive Review / capstone step
P01-S01 - Northstar Commerce Executive Review: Schema memo
Schema memo. A marketplace leadership team needs a defensible monthly performance report, a category concentration view, and an explanation of discrepancies between ordered, paid, and refunded amounts.
- Result grain
- one row per relevant Northstar Commerce table in the memo
- Exact columns
- table_name; row_grain; key_columns; optionality_notes; fanout_risk
SQL editor shortcuts: Ctrl or Command Enter runs the query, Ctrl or Command Shift Enter checks it, Alt H opens the next hint, Ctrl or Command slash toggles a line comment, Ctrl or Command Shift F formats the SQL, and Escape closes transient UI.
Cursor at line 1, column 1.
Project Evidence Contract
- Grain declaration
- one row per relevant Northstar Commerce table in the memo
- Key uniqueness
- table_name is unique in the schema memo output.
- Dependency gate
- First milestone
Validation Checklist
- Verify every required commerce table appears exactly once.
- Name one primary or stable key per table.
- Flag payments, returns, and shipments as independent child facts.
Required Snapshots
- schema memo table
Later revenue and reconciliation milestones depend on this grain and fan-out map.
Project notes and intermediate queries
Notes and saved intermediate queries stay local to this project milestone.
Scenario
A marketplace leadership team needs a defensible monthly performance report, a category concentration view, and an explanation of discrepancies between ordered, paid, and refunded amounts.
Northstar Commerce Executive Review / capstone step
One-sentence task
Schema memo. A marketplace leadership team needs a defensible monthly performance report, a category concentration view, and an explanation of discrepancies between ordered, paid, and refunded amounts.
Project mode disclosure
Persistent brief, milestones, notes, saved intermediate queries, validation checklist, and report export stay together.
Structured output contract
- Result grain
- one row per relevant Northstar Commerce table in the memo
- Exact columns
- table_name; row_grain; key_columns; optionality_notes; fanout_risk
- Source population
- Use the prompt setup plus FROM, JOIN, WHERE, and subquery predicates as the source population. Visible rows are only examples.
- Grouping
- Do not collapse rows unless the contract explicitly asks for aggregation, distinct tuples, or set semantics.
- Ordering
- state grain and key evidence for orders, lines, payments, returns, products, categories, shipments, customers, and calendar months
- Validation
- select-only; hidden deterministic variants.
Relevant tables
Time and difficulty
- Estimated time
- 8 minutes
- Difficulty
- 5/5
Objective and concepts
Produce schema memo evidence with SQL, validation, assumptions, and bounded snapshots.
Glossary links
Concept material
Defensible monthly performance, category concentration, and revenue reconciliation.
Why this works
Defensible monthly performance, category concentration, and revenue reconciliation.
Edge cases
Split captures Failed attempts Partial refunds Multiple returns Products without categories Categories without products Zero-activity months Boundary timestamps Tied category totals Customers with no orders
PostgreSQL note
Project SQL runs locally with PostgreSQL-compatible semantics and project-specific hidden variants.
Assumptions, dialect notes, and common traps
- Duplicate policy
- Preserve duplicate facts unless the prompt explicitly asks for distinct tuples or set semantics.
- Null policy
- Preserve NULL, empty string, zero, and false as distinct values unless the contract says to display a fallback.
- Tie-breakers
- Use every ordering rule in the contract and end tied business metrics with deterministic secondary keys when needed.
- Zero-related entities
- Preserve requested zero-related, no-match, or complete-period entities and make display fallback explicit.
- Numeric tolerance
- Use exact semantic comparison unless the activity explicitly declares a numeric tolerance.
Opened hints
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