diff --git a/broker/migrate/h2/V43__add_message_table_conversation_index.sql b/broker/migrate/h2/V43__add_message_table_conversation_index.sql
new file mode 100755
index 00000000..00aeda6a
--- /dev/null
+++ b/broker/migrate/h2/V43__add_message_table_conversation_index.sql
@@ -0,0 +1 @@
+alter table `t_messages` add INDEX `messages_conv_index` ( `_type`, `_target`, `_line`);
diff --git a/broker/migrate/mysql/V50__add_message_table_conversation_index.sql b/broker/migrate/mysql/V50__add_message_table_conversation_index.sql
new file mode 100755
index 00000000..b7290ca8
--- /dev/null
+++ b/broker/migrate/mysql/V50__add_message_table_conversation_index.sql
@@ -0,0 +1,37 @@
+alter table `t_messages` add INDEX `messages_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_0` add INDEX `messages0_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_1` add INDEX `messages1_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_2` add INDEX `messages2_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_3` add INDEX `messages3_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_4` add INDEX `messages4_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_5` add INDEX `messages5_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_6` add INDEX `messages6_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_7` add INDEX `messages7_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_8` add INDEX `messages8_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_9` add INDEX `messages9_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_10` add INDEX `messages10_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_11` add INDEX `messages11_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_12` add INDEX `messages12_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_13` add INDEX `messages13_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_14` add INDEX `messages14_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_15` add INDEX `messages15_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_16` add INDEX `messages16_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_17` add INDEX `messages17_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_18` add INDEX `messages18_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_19` add INDEX `messages19_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_20` add INDEX `messages20_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_21` add INDEX `messages21_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_22` add INDEX `messages22_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_23` add INDEX `messages23_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_24` add INDEX `messages24_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_25` add INDEX `messages25_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_26` add INDEX `messages26_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_27` add INDEX `messages27_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_28` add INDEX `messages28_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_29` add INDEX `messages29_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_30` add INDEX `messages30_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_31` add INDEX `messages31_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_32` add INDEX `messages32_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_33` add INDEX `messages33_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_34` add INDEX `messages34_conv_index` (`_type`, `_target`, `_line`);
+alter table `t_messages_35` add INDEX `messages35_conv_index` (`_type`, `_target`, `_line`);