Improve speed of getUnreadByConversationAndMarkRead query

ts/sql/Server.node.ts

@@ -3351,6 +3351,7 @@ function getUnreadByConversationAndMarkRead(
 
     const updateExpirationFragment = sqlFragment`
       UPDATE messages
+      INDEXED BY messages_conversationId_expirationStartTimestamp
       SET
         expirationStartTimestamp = ${expirationStartTimestamp}
       WHERE

ts/sql/migrations/1530-update-expiring-index.std.ts

@@ -3,18 +3,15 @@
 
 import type { Database } from '@signalapp/sqlcipher';
 
-export default function updateToSchemaVersion1520(db: Database): void {
+export default function updateToSchemaVersion1530(db: Database): void {
-  db.exec(
-    'DROP INDEX IF EXISTS expiring_message_by_conversation_and_received_at;'
-  );
-
   db.exec(`
     ALTER TABLE messages ADD COLUMN hasExpireTimer INTEGER NOT NULL
     GENERATED ALWAYS AS (COALESCE(expireTimer, 0) > 0) VIRTUAL;     
   `);
 
-  db.exec(`
+  // Deprecated by migration 1540
-    CREATE INDEX messages_conversationId_hasExpireTimer_expirationStartTimestamp
+  // db.exec(`
-    ON messages (conversationId, hasExpireTimer, expirationStartTimestamp);
+  //   CREATE INDEX messages_conversationId_hasExpireTimer_expirationStartTimestamp
-  `);
+  //   ON messages (conversationId, hasExpireTimer, expirationStartTimestamp);
+  // `);
 }

ts/sql/migrations/1540-partial-expiring-index.std.ts

@@ -0,0 +1,16 @@
+// Copyright 2021 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import type { Database } from '@signalapp/sqlcipher';
+
+export default function updateToSchemaVersion1540(db: Database): void {
+  db.exec(
+    'DROP INDEX IF EXISTS messages_conversationId_hasExpireTimer_expirationStartTimestamp;'
+  );
+
+  db.exec(`
+    CREATE INDEX messages_conversationId_expirationStartTimestamp
+    ON messages (conversationId, expirationStartTimestamp)
+    WHERE hasExpireTimer IS 1;
+  `);
+}

ts/sql/migrations/index.node.ts

@@ -129,6 +129,7 @@ import updateToSchemaVersion1500 from './1500-search-polls.std.js';
 import updateToSchemaVersion1510 from './1510-chat-folders-normalize-all-chats.std.js';
 import updateToSchemaVersion1520 from './1520-poll-votes-unread.std.js';
 import updateToSchemaVersion1530 from './1530-update-expiring-index.std.js';
+import updateToSchemaVersion1540 from './1540-partial-expiring-index.std.js';
 
 import { DataWriter } from '../Server.node.js';
 
@@ -1616,6 +1617,7 @@ export const SCHEMA_VERSIONS: ReadonlyArray<SchemaUpdateType> = [
   { version: 1510, update: updateToSchemaVersion1510 },
   { version: 1520, update: updateToSchemaVersion1520 },
   { version: 1530, update: updateToSchemaVersion1530 },
+  { version: 1540, update: updateToSchemaVersion1540 },
 ];
 
 export class DBVersionFromFutureError extends Error {

ts/test-node/sql/migration_1540_test.node.ts

@@ -6,12 +6,12 @@ import { type WritableDB } from '../../sql/Interface.std.js';
 import { sql, sqlFragment } from '../../sql/util.std.js';
 import { createDB, explain, updateToVersion } from './helpers.node.js';
 
-describe('SQL/updateToSchemaVersion1530', () => {
+describe('SQL/updateToSchemaVersion1540', () => {
   let db: WritableDB;
 
   beforeEach(() => {
     db = createDB();
-    updateToVersion(db, 1530);
+    updateToVersion(db, 1540);
   });
   afterEach(() => {
     db.close();
@@ -19,6 +19,7 @@ describe('SQL/updateToSchemaVersion1530', () => {
 
   const CORE_UPDATE_QUERY = sqlFragment`
     UPDATE messages
+    INDEXED BY messages_conversationId_expirationStartTimestamp
     SET
         expirationStartTimestamp = 342342
     WHERE
@@ -48,8 +49,8 @@ describe('SQL/updateToSchemaVersion1530', () => {
 
     assert.strictEqual(
       detail,
-      'SEARCH messages USING INDEX messages_conversationId_hasExpireTimer_expirationStartTimestamp' +
+      'SEARCH messages USING INDEX messages_conversationId_expirationStartTimestamp' +
-        ' (conversationId=? AND hasExpireTimer=? AND expirationStartTimestamp=?)'
+        ' (conversationId=? AND expirationStartTimestamp=?)'
     );
   });
   it('uses index efficiently with null start + no storyId condition', () => {
@@ -62,8 +63,8 @@ describe('SQL/updateToSchemaVersion1530', () => {
 
     assert.strictEqual(
       detail,
-      'SEARCH messages USING INDEX messages_conversationId_hasExpireTimer_expirationStartTimestamp' +
+      'SEARCH messages USING INDEX messages_conversationId_expirationStartTimestamp' +
-        ' (conversationId=? AND hasExpireTimer=? AND expirationStartTimestamp=?)'
+        ' (conversationId=? AND expirationStartTimestamp=?)'
     );
   });
 
@@ -72,8 +73,8 @@ describe('SQL/updateToSchemaVersion1530', () => {
 
     assert.strictEqual(
       detail,
-      'SEARCH messages USING INDEX messages_conversationId_hasExpireTimer_expirationStartTimestamp' +
+      'SEARCH messages USING INDEX messages_conversationId_expirationStartTimestamp' +
-        ' (conversationId=? AND hasExpireTimer=? AND expirationStartTimestamp>?)'
+        ' (conversationId=? AND expirationStartTimestamp>?)'
     );
   });
 
@@ -86,8 +87,8 @@ describe('SQL/updateToSchemaVersion1530', () => {
 
     assert.strictEqual(
       detail,
-      'SEARCH messages USING INDEX messages_conversationId_hasExpireTimer_expirationStartTimestamp' +
+      'SEARCH messages USING INDEX messages_conversationId_expirationStartTimestamp' +
-        ' (conversationId=? AND hasExpireTimer=? AND expirationStartTimestamp>?)'
+        ' (conversationId=? AND expirationStartTimestamp>?)'
     );
   });
 });