Add index to improve speed of MMS count.

app/src/main/java/org/thoughtcrime/securesms/database/MmsDatabase.java

@@ -191,7 +191,8 @@ public class MmsDatabase extends MessageDatabase {
     "CREATE INDEX IF NOT EXISTS mms_thread_date_index ON " + TABLE_NAME + " (" + THREAD_ID + ", " + DATE_RECEIVED + ");",
     "CREATE INDEX IF NOT EXISTS mms_reactions_unread_index ON " + TABLE_NAME + " (" + REACTIONS_UNREAD + ");",
     "CREATE INDEX IF NOT EXISTS mms_is_story_index ON " + TABLE_NAME + " (" + STORY_TYPE + ");",
-    "CREATE INDEX IF NOT EXISTS mms_parent_story_id_index ON " + TABLE_NAME + " (" + PARENT_STORY_ID + ");"
+    "CREATE INDEX IF NOT EXISTS mms_parent_story_id_index ON " + TABLE_NAME + " (" + PARENT_STORY_ID + ");",
+    "CREATE INDEX IF NOT EXISTS mms_thread_story_parent_story_index ON " + TABLE_NAME + " (" + THREAD_ID + ", " + DATE_RECEIVED + "," + STORY_TYPE + "," + PARENT_STORY_ID + ");",
   };
 
   private static final String[] MMS_PROJECTION = new String[] {

app/src/main/java/org/thoughtcrime/securesms/database/helpers/SignalDatabaseMigrations.kt

@@ -194,6 +194,7 @@ object SignalDatabaseMigrations {
   private const val STORIES = 132
   private const val ALLOW_STORY_REPLIES = 133
   private const val GROUP_STORIES = 134
+  private const val MMS_COUNT_INDEX = 135
 
   const val DATABASE_VERSION = 135
 
@@ -2481,6 +2482,10 @@ object SignalDatabaseMigrations {
     if (oldVersion < GROUP_STORIES) {
       db.execSQL("ALTER TABLE groups ADD COLUMN display_as_story INTEGER DEFAULT 0")
     }
+
+    if (oldVersion < MMS_COUNT_INDEX) {
+      db.execSQL("CREATE INDEX IF NOT EXISTS mms_thread_story_parent_story_index ON mms (thread_id, date_received, is_story, parent_story_id)")
+    }
   }
 
   @JvmStatic