[IMPROVE] SlackBridge threads performance improvement (#19338)

app/models/server/models/Messages.js

@@ -22,7 +22,7 @@ export class Messages extends Base {
 		this.tryEnsureIndex({ pinned: 1 }, { sparse: true });
 		this.tryEnsureIndex({ snippeted: 1 }, { sparse: true });
 		this.tryEnsureIndex({ location: '2dsphere' });
-		this.tryEnsureIndex({ slackBotId: 1, slackTs: 1 }, { sparse: true });
+		this.tryEnsureIndex({ slackTs: 1, slackBotId: 1 }, { sparse: true });
 		this.tryEnsureIndex({ unread: 1 }, { sparse: true });
 
 		// discussions

server/startup/migrations/index.js

@@ -206,4 +206,5 @@ import './v206';
 import './v207';
 import './v208';
 import './v209';
+import './v210';
 import './xrun';

server/startup/migrations/v210.js

+import { Migrations } from '../../../app/migrations/server';
+import { Messages } from '../../../app/models/server';
+
+Migrations.add({
+	version: 210,
+	up() {
+		Messages.tryDropIndex({ slackBotId: 1, slackTs: 1 });
+		Messages.tryEnsureIndex({ slackTs: 1, slackBotId: 1 }, { sparse: true });
+	},
+});