Short-circuit storyId predicate to optimize query

ts/sql/migrations/52-optimize-stories.ts

@@ -0,0 +1,38 @@
+// Copyright 2022 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import type { Database } from 'better-sqlite3';
+
+import type { LoggerType } from '../../types/Logging';
+
+export default function updateToSchemaVersion52(
+  currentVersion: number,
+  db: Database,
+  logger: LoggerType
+): void {
+  if (currentVersion >= 52) {
+    return;
+  }
+
+  db.transaction(() => {
+    db.exec(
+      `
+      -- Create indices that don't have storyId in them so that
+      -- '_storyIdPredicate' could be optimized.
+
+      -- See migration 47
+      CREATE INDEX messages_conversation_no_story_id ON messages
+        (conversationId, isStory, received_at, sent_at);
+
+      -- See migration 50
+      CREATE INDEX messages_unread_no_story_id ON messages
+        (conversationId, readStatus, isStory, received_at, sent_at)
+        WHERE readStatus IS NOT NULL;
+      `
+    );
+
+    db.pragma('user_version = 52');
+  })();
+
+  logger.info('updateToSchemaVersion52: success!');
+}

ts/sql/migrations/index.ts

@@ -27,6 +27,7 @@ import updateToSchemaVersion48 from './48-fix-user-initiated-index';
 import updateToSchemaVersion49 from './49-fix-preview-index';
 import updateToSchemaVersion50 from './50-fix-messages-unread-index';
 import updateToSchemaVersion51 from './51-centralize-conversation-jobs';
+import updateToSchemaVersion52 from './52-optimize-stories';
 
 function updateToSchemaVersion1(
   currentVersion: number,
@@ -1917,6 +1918,7 @@ export const SCHEMA_VERSIONS = [
   updateToSchemaVersion49,
   updateToSchemaVersion50,
   updateToSchemaVersion51,
+  updateToSchemaVersion52,
 ];
 
 export function updateSchema(db: Database, logger: LoggerType): void {