diff --git a/examples/c/tmq.c b/examples/c/tmq.c
index 94545dfaad943a3ec5e35ae6859213835d8c4540..e1133c109e72873ddcf4b89a818d878d56a628f1 100644
--- a/examples/c/tmq.c
+++ b/examples/c/tmq.c
@@ -73,7 +73,7 @@ static int32_t init_env() {
   taos_free_result(pRes);
 
   // create database
-  pRes = taos_query(pConn, "create database tmqdb precision 'ns'");
+  pRes = taos_query(pConn, "create database tmqdb precision 'ns' WAL_RETENTION_PERIOD 3600");
   if (taos_errno(pRes) != 0) {
     printf("error in create tmqdb, reason:%s\n", taos_errstr(pRes));
     goto END;
@@ -289,7 +289,7 @@ void consume_repeatly(tmq_t* tmq) {
     }
   }
 
-  free(pAssign);
+  tmq_free_assignment(pAssign);
 
   // let's do it again
   basic_consume_loop(tmq);
diff --git a/include/client/taos.h b/include/client/taos.h
index 8811c4ab64e3ae65085c26ccd791705a98541423..9f5a84fb2267be832fe8bf61fb9648ea28212b60 100644
--- a/include/client/taos.h
+++ b/include/client/taos.h
@@ -288,6 +288,7 @@ DLL_EXPORT int32_t   tmq_commit_sync(tmq_t *tmq, const TAOS_RES *msg);
 DLL_EXPORT void      tmq_commit_async(tmq_t *tmq, const TAOS_RES *msg, tmq_commit_cb *cb, void *param);
 DLL_EXPORT int32_t   tmq_get_topic_assignment(tmq_t *tmq, const char *pTopicName, tmq_topic_assignment **assignment,
                                               int32_t *numOfAssignment);
+DLL_EXPORT void      tmq_free_assignment(tmq_topic_assignment* pAssignment);
 DLL_EXPORT int32_t   tmq_offset_seek(tmq_t *tmq, const char *pTopicName, int32_t vgId, int64_t offset);
 
 /* ----------------------TMQ CONFIGURATION INTERFACE---------------------- */
diff --git a/source/client/src/clientTmq.c b/source/client/src/clientTmq.c
index c38e206a9bd3b4428727edc3042d3e2a8a398022..aff5846092348f5ec7e77938e7a0f11c764affe4 100644
--- a/source/client/src/clientTmq.c
+++ b/source/client/src/clientTmq.c
@@ -2584,6 +2584,14 @@ int32_t tmq_get_topic_assignment(tmq_t* tmq, const char* pTopicName, tmq_topic_a
   }
 }
 
+void tmq_free_assignment(tmq_topic_assignment* pAssignment) {
+    if (pAssignment == NULL) {
+        return;
+    }
+
+    taosMemoryFree(pAssignment);
+}
+
 int32_t tmq_offset_seek(tmq_t* tmq, const char* pTopicName, int32_t vgId, int64_t offset) {
   if (tmq == NULL) {
     tscError("invalid tmq handle, null");