diff --git a/source/libs/function/src/builtins.c b/source/libs/function/src/builtins.c
index e16c6db7c661eb44a3cbe52faf17c9376462180b..d7b8eb268d0720dfc23d897900593c28f9ed286c 100644
--- a/source/libs/function/src/builtins.c
+++ b/source/libs/function/src/builtins.c
@@ -2487,7 +2487,7 @@ const SBuiltinFuncDefinition funcMgtBuiltins[] = {
   {
     .name = "csum",
     .type = FUNCTION_TYPE_CSUM,
-    .classification = FUNC_MGT_INDEFINITE_ROWS_FUNC | FUNC_MGT_TIMELINE_FUNC | FUNC_MGT_FORBID_STREAM_FUNC | FUNC_MGT_CUMULATIVE_FUNC,
+    .classification = FUNC_MGT_INDEFINITE_ROWS_FUNC | FUNC_MGT_SELECT_FUNC | FUNC_MGT_TIMELINE_FUNC | FUNC_MGT_FORBID_STREAM_FUNC | FUNC_MGT_CUMULATIVE_FUNC,
     .translateFunc = translateCsum,
     .getEnvFunc   = getCsumFuncEnv,
     .initFunc     = functionSetup,
diff --git a/source/libs/function/src/builtinsimpl.c b/source/libs/function/src/builtinsimpl.c
index 94e7b77a484744e063aa2ae1e0d4c1f9809fa9b5..05e7041686da0938a20a696fda1dc156586d6343 100644
--- a/source/libs/function/src/builtinsimpl.c
+++ b/source/libs/function/src/builtinsimpl.c
@@ -4781,6 +4781,11 @@ int32_t csumFunction(SqlFunctionCtx* pCtx) {
       }
     }
 
+    // handle selectivity
+    if (pCtx->subsidiaries.num > 0) {
+      appendSelectivityValue(pCtx, i, pos);
+    }
+
     numOfElems++;
   }