diff --git a/source/libs/index/inc/index_cache.h b/source/libs/index/inc/index_cache.h
index 58082294a96d3ba726b6556cf6bffd27af2170ac..544849ff2fab8a1018617db04606e4d4df148502 100644
--- a/source/libs/index/inc/index_cache.h
+++ b/source/libs/index/inc/index_cache.h
@@ -45,6 +45,7 @@ typedef struct IndexCache {
   uint64_t  suid;
 
   pthread_mutex_t mtx;
+  pthread_cond_t  finished;
 } IndexCache;
 
 #define CACHE_VERSION(cache) atomic_load_32(&cache->version)
diff --git a/source/libs/index/src/index.c b/source/libs/index/src/index.c
index 9b7f1c83834374c240ac2fbf505cfdd15859a46d..0bf30d6efabb84b3d060ff6639387b6d8db45c52 100644
--- a/source/libs/index/src/index.c
+++ b/source/libs/index/src/index.c
@@ -399,6 +399,8 @@ int indexFlushCacheTFile(SIndex* sIdx, void* cache) {
   if (sIdx == NULL) { return -1; }
   indexInfo("suid %" PRIu64 " merge cache into tindex", sIdx->suid);
 
+  int64_t st = taosGetTimestampUs();
+
   IndexCache*  pCache = (IndexCache*)cache;
   TFileReader* pReader = tfileGetReaderByCol(sIdx->tindex, pCache->suid, pCache->colName);
   if (pReader == NULL) { indexWarn("empty tfile reader found"); }
@@ -458,6 +460,7 @@ int indexFlushCacheTFile(SIndex* sIdx, void* cache) {
   }
   int ret = indexGenTFile(sIdx, pCache, result);
   indexDestroyTempResult(result);
+
   indexCacheDestroyImm(pCache);
 
   indexCacheIteratorDestroy(cacheIter);
@@ -465,7 +468,14 @@ int indexFlushCacheTFile(SIndex* sIdx, void* cache) {
 
   tfileReaderUnRef(pReader);
   indexCacheUnRef(pCache);
-  return 0;
+
+  int64_t cost = taosGetTimestampUs() - st;
+  if (ret != 0) {
+    indexError("failed to merge, time cost: %" PRId64 "ms", cost / 1000);
+  } else {
+    indexInfo("success to merge , time cost: %" PRId64 "ms", cost / 1000);
+  }
+  return ret;
 }
 void iterateValueDestroy(IterateValue* value, bool destroy) {
   if (destroy) {
@@ -506,7 +516,10 @@ static int indexGenTFile(SIndex* sIdx, IndexCache* cache, SArray* batch) {
   pthread_mutex_unlock(&sIdx->mtx);
   return ret;
 END:
-  tfileWriterClose(tw);
+  if (tw != NULL) {
+    writerCtxDestroy(tw->ctx, true);
+    free(tw);
+  }
   return -1;
 }
 
diff --git a/source/libs/index/src/index_cache.c b/source/libs/index/src/index_cache.c
index 7a4beb21192857a8fccc5e9f29b25255041632a1..d43c9f9cce1a421b80995024458417ca6a30c769 100644
--- a/source/libs/index/src/index_cache.c
+++ b/source/libs/index/src/index_cache.c
@@ -53,7 +53,10 @@ IndexCache* indexCacheCreate(SIndex* idx, uint64_t suid, const char* colName, in
   cache->version = 0;
   cache->suid = suid;
   cache->occupiedMem = 0;
+
   pthread_mutex_init(&cache->mtx, NULL);
+  pthread_cond_init(&cache->finished, NULL);
+
   indexCacheRef(cache);
   return cache;
 }
@@ -124,6 +127,7 @@ void indexCacheDestroyImm(IndexCache* cache) {
   pthread_mutex_lock(&cache->mtx);
   tbl = cache->imm;
   cache->imm = NULL;  // or throw int bg thread
+  pthread_cond_broadcast(&cache->finished);
   pthread_mutex_unlock(&cache->mtx);
 
   indexMemUnRef(tbl);
@@ -136,6 +140,9 @@ void indexCacheDestroy(void* cache) {
   indexMemUnRef(pCache->imm);
   free(pCache->colName);
 
+  pthread_mutex_destroy(&pCache->mtx);
+  pthread_cond_destroy(&pCache->finished);
+
   free(pCache);
 }
 
@@ -180,9 +187,10 @@ static void indexCacheMakeRoomForWrite(IndexCache* cache) {
       break;
     } else if (cache->imm != NULL) {
       // TODO: wake up by condition variable
-      pthread_mutex_unlock(&cache->mtx);
-      taosMsleep(50);
-      pthread_mutex_lock(&cache->mtx);
+      // pthread_mutex_unlock(&cache->mtx);
+      pthread_cond_wait(&cache->finished, &cache->mtx);
+      // taosMsleep(50);
+      // pthread_mutex_lock(&cache->mtx);
     } else {
       indexCacheRef(cache);
       cache->imm = cache->mem;
diff --git a/source/libs/index/test/indexTests.cc b/source/libs/index/test/indexTests.cc
index 9c92af26a23a6a994ae3d7b20d36857d52f0b656..5438f88b7688e8c5f6c0c6251400ad73b4296f5f 100644
--- a/source/libs/index/test/indexTests.cc
+++ b/source/libs/index/test/indexTests.cc
@@ -28,7 +28,7 @@
 #include "tutil.h"
 using namespace std;
 
-#define NUM_OF_THREAD 5
+#define NUM_OF_THREAD 10
 
 class DebugInfo {
  public:
@@ -882,8 +882,8 @@ static void single_write_and_search(IndexObj* idx) {
 static void multi_write_and_search(IndexObj* idx) {
   int target = idx->SearchOne("tag1", "Hello");
   target = idx->SearchOne("tag2", "Test");
-  idx->WriteMultiMillonData("tag1", "Hello", 100 * 10000);
-  idx->WriteMultiMillonData("tag2", "Test", 100 * 10000);
+  idx->WriteMultiMillonData("tag1", "hello world test", 100 * 10000);
+  idx->WriteMultiMillonData("tag2", "world test nothing", 100 * 10000);
 }
 TEST_F(IndexEnv2, testIndex_serarch_cache_and_tfile) {
   std::string path = "/tmp/cache_and_tfile";