tinySQL Catalog & Scheduler Demo (catalog_demo)

Demonstrates the tinySQL catalog and job-scheduler APIs. It registers tables, views, and functions in the catalog, then schedules recurring and one-shot SQL jobs backed by the real tinySQL execution engine.

What it shows

Concept	Description
Catalog registration	RegisterTable, RegisterView, RegisterFunction
Catalog queries	GetTables, GetColumns, GetTables introspection
INTERVAL job	SQL query re-run every N milliseconds
ONCE job	SQL query scheduled at an absolute point in time
JobExecutor	Custom executor that parses and executes SQL, printing results
Scheduler lifecycle	Start / Stop a storage.Scheduler

Build

go build -o catalog_demo ./cmd/catalog_demo

Run

./catalog_demo

No flags needed. The demo runs for about 6 seconds, prints job output, reports job status, then exits.

Expected output (abridged)

=== tinySQL Catalog & Scheduler Demo ===

✓ Seeded events table with 20 rows

1. Registering tables in catalog...

2. Tables registered in catalog:
   - main.events          (type: table, created: 12:00:01)
   - main.event_stats     (type: table, created: 12:00:01)

3. Columns for 'events':
   - id              INT    (position 0, nullable: true)
   - kind            TEXT   (position 1, nullable: true)
   ...

4. Registering views...
   - registered view: recent_events

5. Registering functions...
   - registered function: json_get

6. Creating scheduled jobs...
   - INTERVAL job "refresh_event_stats" every 2s: SELECT kind, COUNT(*) ...
   - ONCE job "integrity_check" at 12:00:02: SELECT COUNT(*) ...

7. Starting scheduler (jobs will execute real SQL)...

8. Monitoring jobs for 6 seconds (watch log output)...
   job result (2 rows): kind=click, total=13
   ...

9. Job status:
   refresh_event_stats       enabled | last: 12:00:06 | next: 12:00:08
   integrity_check           enabled | last: 12:00:02 | next: n/a

10. Stopping scheduler...

=== Demo Complete ===

Key APIs used

catalog := db.Catalog()

catalog.RegisterTable("main", "events", []storage.Column{...})
catalog.RegisterView("main", "recent_events", "SELECT ...")
catalog.RegisterFunction(&storage.CatalogFunction{...})
catalog.RegisterJob(&storage.CatalogJob{
    ScheduleType: "INTERVAL",
    IntervalMs:   2000,
})

scheduler := storage.NewScheduler(db, executor)
scheduler.Start()
scheduler.Stop()

See catalog.go and scheduler.go for the full API.