Replace notes(userId) index with (userId, id)

This improves performance of queries searching posts by a given user,
optionally with a provided range of dates, and then using ORDER BY to
sort posts by date.

Examples of such queries include: viewing posts by a given user, as
well as checking when the last post by a given user was written for
Mastodon API.

packages/backend/migration/1736888704471-NoteUserIdIdIndex.js

@@ -0,0 +1,11 @@
+export class NoteUserIdIdIndex1736888704471 {
+	name = 'NoteUserIdIdIndex1736888704471'
+
+	async up(queryRunner) {
+		await queryRunner.query(`CREATE INDEX "IDX_note_userId_id" ON "note" ("userId", "id") `);
+	}
+
+	async down(queryRunner) {
+		await queryRunner.query(`DROP INDEX "public"."IDX_note_userId_id"`);
+	}
+}

packages/backend/src/models/Note.ts

@@ -15,6 +15,7 @@ import type { MiDriveFile } from './DriveFile.js';
 @Index('IDX_NOTE_MENTIONS', { synchronize: false })
 @Index('IDX_NOTE_FILE_IDS', { synchronize: false })
 @Index('IDX_NOTE_VISIBLE_USER_IDS', { synchronize: false })
+@Index('IDX_note_userId_id', ['userId', 'id'])
 export class MiNote {
 	@PrimaryColumn(id())
 	public id: string;