diff --git a/vnpy/trader/database/database_mongo.py b/vnpy/trader/database/database_mongo.py
index f1e7c4a9..19292e66 100644
--- a/vnpy/trader/database/database_mongo.py
+++ b/vnpy/trader/database/database_mongo.py
@@ -55,7 +55,7 @@ class DbBarData(Document):
     meta = {
         "indexes": [
             {
-                "fields": ("datetime", "interval", "symbol", "exchange"),
+                "fields": ("symbol", "exchange", "interval", "datetime"),
                 "unique": True,
             }
         ]
@@ -150,7 +150,7 @@ class DbTickData(Document):
     meta = {
         "indexes": [
             {
-                "fields": ("datetime", "symbol", "exchange"),
+                "fields": ("symbol", "exchange", "datetime"),
                 "unique": True,
             }
         ],
diff --git a/vnpy/trader/database/database_sql.py b/vnpy/trader/database/database_sql.py
index 41e54856..b2a39460 100644
--- a/vnpy/trader/database/database_sql.py
+++ b/vnpy/trader/database/database_sql.py
@@ -82,7 +82,7 @@ def init_models(db: Database, driver: Driver):
 
         class Meta:
             database = db
-            indexes = ((("datetime", "interval", "symbol", "exchange"), True),)
+            indexes = ((("symbol", "exchange", "interval", "datetime"), True),)
 
         @staticmethod
         def from_bar(bar: BarData):
@@ -195,7 +195,7 @@ def init_models(db: Database, driver: Driver):
 
         class Meta:
             database = db
-            indexes = ((("datetime", "symbol", "exchange"), True),)
+            indexes = ((("symbol", "exchange", "datetime"), True),)
 
         @staticmethod
         def from_tick(tick: TickData):