agent: add indexes to improve slow queries performance (#823)

src/Simplex/Messaging/Agent/Store/SQLite.hs

@@ -1106,7 +1106,7 @@ deleteSndMsgsExpired db ttl = do
   cutoffTs <- addUTCTime (- ttl) <$> getCurrentTime
   DB.execute
     db
-    "DELETE FROM messages WHERE internal_snd_id IS NOT NULL AND internal_ts < ?"
+    "DELETE FROM messages WHERE internal_ts < ? AND internal_snd_id IS NOT NULL"
     (Only cutoffTs)
 
 createRatchetX3dhKeys :: DB.Connection -> ConnId -> C.PrivateKeyX448 -> C.PrivateKeyX448 -> IO ()

src/Simplex/Messaging/Agent/Store/SQLite/Migrations.hs

@@ -65,6 +65,7 @@ import Simplex.Messaging.Agent.Store.SQLite.Migrations.M20230615_ratchet_sync
 import Simplex.Messaging.Agent.Store.SQLite.Migrations.M20230701_delivery_receipts
 import Simplex.Messaging.Agent.Store.SQLite.Migrations.M20230720_delete_expired_messages
 import Simplex.Messaging.Agent.Store.SQLite.Migrations.M20230722_indexes
+import Simplex.Messaging.Agent.Store.SQLite.Migrations.M20230814_indexes
 import Simplex.Messaging.Encoding.String
 import Simplex.Messaging.Parsers (dropPrefix, sumTypeJSON)
 import Simplex.Messaging.Transport.Client (TransportHost)
@@ -96,7 +97,8 @@ schemaMigrations =
     ("m20230615_ratchet_sync", m20230615_ratchet_sync, Just down_m20230615_ratchet_sync),
     ("m20230701_delivery_receipts", m20230701_delivery_receipts, Just down_m20230701_delivery_receipts),
     ("m20230720_delete_expired_messages", m20230720_delete_expired_messages, Just down_m20230720_delete_expired_messages),
-    ("m20230722_indexes", m20230722_indexes, Just down_m20230722_indexes)
+    ("m20230722_indexes", m20230722_indexes, Just down_m20230722_indexes),
+    ("m20230814_indexes", m20230814_indexes, Just down_m20230814_indexes)
   ]
 
 -- | The list of migrations in ascending order by date

src/Simplex/Messaging/Agent/Store/SQLite/Migrations/M20230814_indexes.hs

@@ -0,0 +1,22 @@
+{-# LANGUAGE QuasiQuotes #-}
+
+module Simplex.Messaging.Agent.Store.SQLite.Migrations.M20230814_indexes where
+
+import Database.SQLite.Simple (Query)
+import Database.SQLite.Simple.QQ (sql)
+
+m20230814_indexes :: Query
+m20230814_indexes =
+  [sql|
+DROP INDEX idx_messages_internal_snd_id_ts;
+
+CREATE INDEX idx_messages_internal_ts ON messages(internal_ts);
+|]
+
+down_m20230814_indexes :: Query
+down_m20230814_indexes =
+  [sql|
+DROP INDEX idx_messages_internal_ts;
+
+CREATE INDEX idx_messages_internal_snd_id_ts ON messages(internal_snd_id, internal_ts);
+|]

src/Simplex/Messaging/Agent/Store/SQLite/Migrations/agent_schema.sql

@@ -467,13 +467,10 @@ CREATE INDEX idx_snd_messages_rcpt_internal_id ON snd_messages(
   conn_id,
   rcpt_internal_id
 );
-CREATE INDEX idx_messages_internal_snd_id_ts ON messages(
-  internal_snd_id,
-  internal_ts
-);
 CREATE INDEX idx_processed_ratchet_key_hashes_created_at ON processed_ratchet_key_hashes(
   created_at
 );
 CREATE INDEX idx_encrypted_rcv_message_hashes_created_at ON encrypted_rcv_message_hashes(
   created_at
 );
+CREATE INDEX idx_messages_internal_ts ON messages(internal_ts);