[v0.3.1] Batch Dependency Resolution for 10× Performance

[dean0x]

Overview

Replace N+1 queries with single batch UPDATE + JOIN for dependency resolution.

Current Behavior

When a task completes, we resolve dependencies one-by-one:

for (const dependent of dependents) {
  await resolveDependency(dependent.taskId, taskId, 'completed');
}

Proposed Solution

Use single batch query with JOIN:

UPDATE task_dependencies
SET resolution = ?, resolved_at = ?
FROM (
  SELECT task_id FROM task_dependencies WHERE depends_on_task_id = ?
) AS deps
WHERE task_dependencies.task_id = deps.task_id
  AND task_dependencies.depends_on_task_id = ?;

Benefits

• 7-10× faster for tasks with many dependents
• Critical for tasks with 10+ dependents
• Reduces database round trips significantly

Effort Estimate

2-4 hours

References

• ROADMAP.md v0.3.1 section
• Pre-PR review document

Priority

HIGH - Critical for production performance with complex dependency graphs