diff --git a/fe/fe-core/src/main/java/org/apache/doris/catalog/OdbcTable.java b/fe/fe-core/src/main/java/org/apache/doris/catalog/OdbcTable.java
index d937008d44..835e3c1a3c 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/catalog/OdbcTable.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/catalog/OdbcTable.java
@@ -274,7 +274,7 @@ public class OdbcTable extends Table {
                         "utf8");
                 break;
             case POSTGRESQL:
-                connectString = String.format("Driver=%s;Server=%s;Port=%s;DataBase=%s;Uid=%s;Pwd=%s;charset=%s",
+                connectString = String.format("Driver=%s;Server=%s;Port=%s;DataBase=%s;Uid=%s;Pwd=%s;charset=%s;UseDeclareFetch=1;Fetch=4096",
                         getOdbcDriver(),
                         getHost(),
                         getPort(),
@@ -282,6 +282,7 @@ public class OdbcTable extends Table {
                         getUserName(),
                         getPasswd(),
                         "utf8");
+                break;
             case MYSQL:
                 connectString = String.format("Driver=%s;Server=%s;Port=%s;DataBase=%s;Uid=%s;Pwd=%s;charset=%s;forward_cursor=1;no_cache=1",
                         getOdbcDriver(),
diff --git a/fe/fe-core/src/main/java/org/apache/doris/mysql/MysqlProto.java b/fe/fe-core/src/main/java/org/apache/doris/mysql/MysqlProto.java
index 3120eab648..5aa9eb234c 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/mysql/MysqlProto.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/mysql/MysqlProto.java
@@ -172,7 +172,10 @@ public class MysqlProto {
         // with password.
         // So Doris support the Protocol::AuthSwitchRequest to tell client to keep the default password plugin
         // which Doris is using now.
-        if (!handshakePacket.checkAuthPluginSameAsDoris(authPacket.getPluginName())) {
+        // Note: Check the authPacket whether support plugin auth firstly, before we check AuthPlugin between doris and client
+        // to compatible with older version: like mysql 5.1
+        if (authPacket.getCapability().isPluginAuth() &&
+                !handshakePacket.checkAuthPluginSameAsDoris(authPacket.getPluginName())) {
             // 1. clear the serializer
             serializer.reset();
             // 2. build the auth switch request and send to the client