par2_files back on the NVMe: the merger reads it per set, a random read per row on the HDD

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

database/migrations/1770000003700_par2_files_back_on_nvme.ts

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+import { BaseSchema } from '@adonisjs/lucid/schema'
+
+/**
+ * par2_files, with its indexes, back in the catalog's tablespace (default_tablespace: nvme on homelab), out of
+ * CHUNK_TABLESPACE where 3200 put it: the merger matches every new file hash against it and reads each set's rows, a
+ * random read per row on the HDD (~1,090 sets/min, a full round ~28 h; LOG.md 2026-10-15 (58)). Homelab rebuilt it
+ * there by hand without the complete and judged sets' rows (app/services/par2_pruner.ts; LOG.md 2026-10-16 (60)); a
+ * no-op where it's there already, or without a default tablespace (tests).
+ */
+export default class extends BaseSchema {
+  async up() {
+    this.defer(async (db) => {
+      const { rows: setting } = await db.rawQuery(`SELECT current_setting('default_tablespace') AS target`)
+      const target = setting[0].target
+      if (!target) return
+      const { rows } = await db.rawQuery(
+        `SELECT c.relname, c.relkind FROM pg_class c LEFT JOIN pg_tablespace t ON t.oid = c.reltablespace
+         WHERE (c.relname = 'par2_files' OR c.oid IN (SELECT indexrelid FROM pg_index WHERE indrelid = 'par2_files'::regclass))
+           AND coalesce(t.spcname, 'pg_default') <> ?`,
+        [target]
+      )
+      for (const { relname, relkind } of rows) {
+        await db.rawQuery(`ALTER ${relkind === 'i' ? 'INDEX' : 'TABLE'} ${relname} SET TABLESPACE ${target}`)
+      }
+    })
+  }
+
+  async down() {}
+}