writeonce/docs/examples/employee

employee — the database track's acceptance workload

Status: target workload — does not compile on today's toolchain. This sample is written ahead of the features it exercises, exactly as log-watcher was written ahead of iterations 5–7: the sample is the test, and the plans compile toward it. It becomes buildable when iteration 9 (engine: 2026-08-01-db-engine-binding.md) and iteration 9b (query surface: 2026-08-15-employee-relations-query.md) land. Normative semantics: the 9b spec.

Two @table classes and every 9b feature load-bearing:

Mode	What it proves
employee seed	insert + WAL-before-ack; a second run catches the departments.name @unique trap (SEED-DUP, exit 3)
employee report	group … by … into g lowered as one hash pass; count/avg/min/max per department; order by avg(g.salary) desc; whole-query sum for payroll
employee staff <dept>	unique-name index probe (asserted via the engine's probe counter, not assumed), backlink scan one way, e.dept.name ref navigation the other
employee raise <dept> <pct>	update through a query result; a missing department takes the empty-query path
employee drop <dept>	delete restrict: a department with staff traps (exit 4); the trap code is the acceptance's assertion

The engine lives in database/ (statically linked into wovm — still one binary). Rows are RAM-authoritative, WAL-durable; a kill -9 between seed and report followed by an identical report is part of the acceptance script (iteration 9's replay, proven on this workload).

Data shape: Department { name @unique, staff: backlink Employee.dept }, Employee { name, salary (cents), hired (epoch ms), dept: ref Department }, indexes [name], [dept], [dept, salary]. Salaries wrap like all language arithmetic; avg/min/max are ?Int because an empty group is data, not a fault.