diff --git a/src/sql/engine/px/ob_px_tenant_target_monitor.cpp b/src/sql/engine/px/ob_px_tenant_target_monitor.cpp
index f3c3a790ca400d53d284905388f1a05432d5f84f..62dbfadf9d5003565b19ee886a0b1df4ae0b64d6 100644
--- a/src/sql/engine/px/ob_px_tenant_target_monitor.cpp
+++ b/src/sql/engine/px/ob_px_tenant_target_monitor.cpp
@@ -319,9 +319,16 @@ int ObPxTenantTargetMonitor::update_peer_target_used(const ObAddr &server, int64
     if (ret != OB_HASH_NOT_EXIST) {
       LOG_WARN("get refactored failed", K(ret));
     } else {
-      target_usage.set_peer_used(peer_used);
-      if (OB_FAIL(global_target_usage_.set_refactored(server, target_usage))) {
-        LOG_WARN("set refactored failed", K(ret));
+      ObLockGuard<ObSpinLock> lock_guard(spin_lock_);
+      if (OB_FAIL(global_target_usage_.get_refactored(server, target_usage))) {
+        if (ret != OB_HASH_NOT_EXIST) {
+          LOG_WARN("get refactored failed", K(ret));
+        } else {
+          target_usage.set_peer_used(peer_used);
+          if (OB_FAIL(global_target_usage_.set_refactored(server, target_usage))) {
+            LOG_WARN("set refactored failed", K(ret));
+          }
+        }
       }
     }
   } else {
@@ -361,6 +368,7 @@ int ObPxTenantTargetMonitor::get_global_target_usage(const hash::ObHashMap<ObAdd
 int ObPxTenantTargetMonitor::reset_statistics(uint64_t version)
 {
   int ret = OB_SUCCESS;
+  ObLockGuard<ObSpinLock> lock_guard(spin_lock_);
   global_target_usage_.clear();
   if (OB_FAIL(global_target_usage_.set_refactored(server_, ServerTargetUsage()))) {
     LOG_WARN("set refactored failed", K(ret));
diff --git a/src/sql/optimizer/ob_px_resource_analyzer.cpp b/src/sql/optimizer/ob_px_resource_analyzer.cpp
index a3390278a1553aa98295bfdaa7362738245db8a8..4c5412bd53654edefead42d18b34a248e7594d4c 100644
--- a/src/sql/optimizer/ob_px_resource_analyzer.cpp
+++ b/src/sql/optimizer/ob_px_resource_analyzer.cpp
@@ -593,7 +593,10 @@ int ObPxResourceAnalyzer::schedule_dfo(
     const int64_t group = 1;
     groups += group;
     ObHashSet<ObAddr> &addr_set = dfo.location_addr_;
-    if (OB_FAIL(update_parallel_map(current_thread_map, addr_set, dfo.get_dop()))) {
+    // we assume that should allocate same thread count for each sqc in the dfo.
+    // this may not true. but we can't decide the real count for each sqc. just let it be for now
+    const int64_t dop_per_addr = 0 == addr_set.size() ? dfo.get_dop() : (dfo.get_dop() + addr_set.size() - 1) / addr_set.size();
+    if (OB_FAIL(update_parallel_map(current_thread_map, addr_set, dop_per_addr))) {
       LOG_WARN("increase current thread map failed", K(ret));
     } else if (OB_FAIL(update_parallel_map(current_group_map, addr_set, group))) {
       LOG_WARN("increase current group map failed", K(ret));
@@ -616,7 +619,8 @@ int ObPxResourceAnalyzer::finish_dfo(
     const int64_t group = 1;
     groups -= group;
     ObHashSet<ObAddr> &addr_set = dfo.location_addr_;
-    if (OB_FAIL(update_parallel_map(current_thread_map, addr_set, -dfo.get_dop()))) {
+    const int64_t dop_per_addr = 0 == addr_set.size() ? dfo.get_dop() : (dfo.get_dop() + addr_set.size() - 1) / addr_set.size();
+    if (OB_FAIL(update_parallel_map(current_thread_map, addr_set, -dop_per_addr))) {
       LOG_WARN("decrease current thread map failed", K(ret));
     } else if (OB_FAIL(update_parallel_map(current_group_map, addr_set, -group))) {
       LOG_WARN("decrease current group map failed", K(ret));