Improve repair performance in cases where there are a lot of finished…

… jobs with dependencies

src/pg-backend.ts

@@ -348,18 +348,15 @@ export class PgBackend {
       DELETE FROM minion_workers WHERE notified < NOW() - INTERVAL '1 millisecond' * ${minion.missingAfter}
     `;
 
-    // Old jobs with no unresolved dependencies and expired jobs
+    // Old jobs
     await pg.query`
-      DELETE FROM minion_jobs WHERE id IN (
-        SELECT j.id FROM minion_jobs AS j LEFT JOIN minion_jobs AS children
-          ON children.state != 'finished' AND ARRAY_LENGTH(children.parents, 1) > 0 AND j.id = ANY(children.parents)
-        WHERE j.state = 'finished' AND j.finished <= NOW() - INTERVAL '1 millisecond' * ${minion.removeAfter}
-          AND children.id IS NULL
-        UNION ALL
-        SELECT id FROM minion_jobs WHERE state = 'inactive' AND expires <= NOW()
-      )
+      DELETE FROM minion_jobs
+      WHERE state = 'finished' AND finished <= NOW() - INTERVAL '1 millisecond' * ${minion.removeAfter}
     `;
 
+    // Expired jobs
+    await pg.query`DELETE FROM minion_jobs WHERE  state = 'inactive' AND expires <= NOW()`;
+
     // Jobs with missing worker (can be retried)
     const jobs = await pg.query<JobWithMissingWorkerResult>`
       SELECT id, retries FROM minion_jobs AS j

test/pg.js

@@ -1027,9 +1027,9 @@ t.test('PostgreSQL backend', skip, async t => {
     t.same((await job4.info()).parents, [id, id2]);
     t.equal((await minion.stats()).finished_jobs, 2);
     await minion.repair();
-    t.equal((await minion.stats()).finished_jobs, 2);
+    t.equal((await minion.stats()).finished_jobs, 0);
     t.ok(await job4.finish());
-    t.equal((await minion.stats()).finished_jobs, 3);
+    t.equal((await minion.stats()).finished_jobs, 1);
     await minion.repair();
     t.equal((await minion.stats()).finished_jobs, 0);