diff --git a/src/util/inc/tkvstore.h b/src/util/inc/tkvstore.h
index 724c94e21d..a57d0e95cf 100644
--- a/src/util/inc/tkvstore.h
+++ b/src/util/inc/tkvstore.h
@@ -46,11 +46,12 @@ typedef struct {
 } SKVStore;
 
 int       tdCreateKVStore(char *fname);
-int       tdDestroyKVStore();
+int       tdDestroyKVStore(char *fname);
 SKVStore *tdOpenKVStore(char *fname, iterFunc iFunc, afterFunc aFunc, void *appH);
 void      tdCloseKVStore(SKVStore *pStore);
 int       tdKVStoreStartCommit(SKVStore *pStore);
-int       tdUpdateRecordInKVStore(SKVStore *pStore, uint64_t uid, void *cont, int contLen);
+int       tdUpdateKVStoreRecord(SKVStore *pStore, uint64_t uid, void *cont, int contLen);
+int       tdDropKVStoreRecord(SKVStore *pStore, uint64_t uid);
 int       tdKVStoreEndCommit(SKVStore *pStore);
 
 #ifdef __cplusplus
diff --git a/src/util/src/tkvstore.c b/src/util/src/tkvstore.c
index f6ccdc9333..0c6c21eb4f 100644
--- a/src/util/src/tkvstore.c
+++ b/src/util/src/tkvstore.c
@@ -49,34 +49,47 @@ static char *    tdGetKVStoreNewFname(char *fdata);
 static void      tdFreeKVStore(SKVStore *pStore);
 static int       tdUpdateKVStoreHeader(int fd, char *fname, SStoreInfo *pInfo);
 static int       tdLoadKVStoreHeader(int fd, char *fname, SStoreInfo *pInfo);
-// static void *    tdEncodeKVRecord(void *buf, SKVRecord *pRecord);
+static void *    tdEncodeKVRecord(void *buf, SKVRecord *pRecord);
 static void *    tdDecodeKVRecord(void *buf, SKVRecord *pRecord);
 static int       tdRestoreKVStore(SKVStore *pStore);
 
 int tdCreateKVStore(char *fname) {
-  char *tname = strdup(fname);
-  if (tname == NULL) return TSDB_CODE_COM_OUT_OF_MEMORY;
-
   int fd = open(fname, O_RDWR | O_CREAT, 0755);
   if (fd < 0) {
     uError("failed to open file %s since %s", fname, strerror(errno));
-    return TAOS_SYSTEM_ERROR(errno);
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    return -1;
   }
 
-  int code = tdInitKVStoreHeader(fd, fname);
-  if (code != TSDB_CODE_SUCCESS) return code;
+  if (tdInitKVStoreHeader(fd, fname) < 0) {
+    close(fd);
+    return -1;
+  }
 
   if (fsync(fd) < 0) {
     uError("failed to fsync file %s since %s", fname, strerror(errno));
-    return TAOS_SYSTEM_ERROR(errno);
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    close(fd);
+    return -1;
   }
 
   if (close(fd) < 0) {
     uError("failed to close file %s since %s", fname, strerror(errno));
-    return TAOS_SYSTEM_ERROR(errno);
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    return -1;
   }
 
-  return TSDB_CODE_SUCCESS;
+  return 0;
+}
+
+int tdDestroyKVStore(char *fname) {
+  if (remove(fname) < 0) {
+    uError("failed to remove file %s since %s", fname, strerror(errno));
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    return -1;
+  }
+
+  return 0;
 }
 
 SKVStore *tdOpenKVStore(char *fname, iterFunc iFunc, afterFunc aFunc, void *appH) {
@@ -101,23 +114,31 @@ SKVStore *tdOpenKVStore(char *fname, iterFunc iFunc, afterFunc aFunc, void *appH
       goto _err;
     }
 
-    // TODO: rewind the file
     if (tdLoadKVStoreHeader(pStore->sfd, pStore->fsnap, &info) < 0) goto _err;
 
     if (ftruncate(pStore->fd, info.size) < 0) {
-      uError("failed to truncate %s since %s", pStore->fname, strerror(errno));
+      uError("failed to truncate %s to " PRId64 " size since %s", pStore->fname, info.size, strerror(errno));
       terrno = TAOS_SYSTEM_ERROR(errno);
       goto _err;
     }
 
+    if (tdUpdateKVStoreHeader(pStore->fd, pStore->fname, &info) < 0) goto _err;
+
     close(pStore->sfd);
     pStore->sfd = -1;
     remove(pStore->fsnap);
   }
 
-  // TODO: Recover from the file
-  terrno = tdUpdateKVStoreHeader(pStore->fd, pStore->fname, &info);
-  if (terrno != TSDB_CODE_SUCCESS) goto _err;
+  if (tdLoadKVStoreHeader(pStore->fd, pStore->fname, &info) < 0) goto _err;
+
+  struct stat tfstat;
+  if (fstat(pStore->fd, &tfstat) < 0) {
+    uError("failed to fstat file %s since %s", pStore->fname, strerror(errno));
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    goto _err;
+  }
+
+  ASSERT(info.size == tfstat.st_size);
 
   if (lseek(pStore->fd, TD_KVSTORE_HEADER_SIZE, SEEK_SET) < 0) {
     uError("failed to lseek file %s since %s", pStore->fname, strerror(errno));
@@ -125,8 +146,9 @@ SKVStore *tdOpenKVStore(char *fname, iterFunc iFunc, afterFunc aFunc, void *appH
     goto _err;
   }
 
-  terrno = tdRestoreKVStore(pStore);
-  if (terrno != TSDB_CODE_SUCCESS) goto _err;
+  pStore->info.size += TD_KVSTORE_HEADER_SIZE;
+
+  if (tdRestoreKVStore(pStore) < 0) goto _err;
 
   close(pStore->fd);
   pStore->fd = -1;
@@ -146,7 +168,11 @@ _err:
   return NULL;
 }
 
+void tdCloseKVStore(SKVStore *pStore) { tdFreeKVStore(pStore); }
+
 int tdKVStoreStartCommit(SKVStore *pStore) {
+  ASSERT(pStore->fd < 0);
+
   pStore->fd = open(pStore->fname, O_RDWR);
   if (pStore->fd < 0) {
     uError("failed to open file %s since %s", pStore->fname, strerror(errno));
@@ -180,6 +206,14 @@ int tdKVStoreStartCommit(SKVStore *pStore) {
   }
   pStore->sfd = -1;
 
+  if (lseek(pStore->fd, 0, SEEK_END) < 0) {
+    uError("failed to lseek file %s since %s", pStore->fname, strerror(errno));
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    goto _err;
+  }
+
+  ASSERT(pStore->info.size == lseek(pStore->fd, 0, SEEK_CUR));
+
   return 0;
 
 _err:
@@ -195,11 +229,50 @@ _err:
   return -1;
 }
 
+int tdUpdateKVStoreRecord(SKVStore *pStore, uint64_t uid, void *cont, int contLen) {
+  SKVRecord *pRecord = taosHashGet(pStore->map, (void *)&uid, sizeof(uid));
+  if (pRecord != NULL) {
+    pStore->info.tombSize += (pRecord->size + sizeof(SKVRecord));
+  }
+
+  // TODO
+  return 0;
+}
+
+int tdDropKVStoreRecord(SKVStore *pStore, uint64_t uid) {
+  SKVRecord rInfo = {0};
+  char      buf[128] = "\0";
+
+  SKVRecord *pRecord = taosHashGet(pStore->map, &uid, sizeof(uid));
+  if (pRecord == NULL) {
+    uError("failed to drop KV store record with key " PRIu64 " since not find", uid);
+    return -1;
+  }
+
+  rInfo.offset = -pRecord->offset;
+  rInfo.uid = pRecord->uid;
+  rInfo.size = pRecord->size;
+
+  void *pBuf = tdEncodeKVRecord(buf, &rInfo);
+
+  if (twrite(pStore->fd, buf, POINTER_DISTANCE(pBuf, buf)) < POINTER_DISTANCE(pBuf, buf)) {
+    uError("failed to write %d bytes to file %s since %s", POINTER_DISTANCE(pBuf, buf), pStore->fname, strerror(errno));
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    return -1;
+  }
+
+  pStore->info.size += POINTER_DISTANCE(pBuf, buf);
+  pStore->info.nDels++;
+  pStore->info.nRecords--;
+  pStore->info.tombSize += (rInfo.size + sizeof(SKVRecord) * 2);
+
+  return 0;
+}
+
 int tdKVStoreEndCommit(SKVStore *pStore) {
   ASSERT(pStore->fd > 0);
 
-  terrno = tdUpdateKVStoreHeader(pStore->fd, pStore->fname, &(pStore->info));
-  if (terrno != TSDB_CODE_SUCCESS) return -1;
+  if (tdUpdateKVStoreHeader(pStore->fd, pStore->fname, &(pStore->info)) < 0) return -1;
 
   if (fsync(pStore->fd) < 0) {
     uError("failed to fsync file %s since %s", pStore->fname, strerror(errno));
@@ -212,6 +285,7 @@ int tdKVStoreEndCommit(SKVStore *pStore) {
     terrno = TAOS_SYSTEM_ERROR(errno);
     return -1;
   }
+  pStore->fd = -1;
 
   remove(pStore->fsnap);
   return 0;
@@ -220,14 +294,21 @@ int tdKVStoreEndCommit(SKVStore *pStore) {
 static int tdLoadKVStoreHeader(int fd, char *fname, SStoreInfo *pInfo) {
   char buf[TD_KVSTORE_HEADER_SIZE] = "\0";
 
+  if (lseek(fd, 0, SEEK_SET) < 0) {
+    uError("failed to lseek file %s since %s", fname, strerror(errno));
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    return -1;
+  }
+
   if (tread(fd, buf, TD_KVSTORE_HEADER_SIZE) < TD_KVSTORE_HEADER_SIZE) {
-    uError("failed to read file %s since %s", fname, strerror(errno));
+    uError("failed to read %d bytes from file %s since %s", TD_KVSTORE_HEADER_SIZE, fname, strerror(errno));
     terrno = TAOS_SYSTEM_ERROR(errno);
     return -1;
   }
 
   if (!taosCheckChecksumWhole((uint8_t *)buf, TD_KVSTORE_HEADER_SIZE)) {
     uError("file %s is broken", fname);
+    terrno = TSDB_CODE_COM_FILE_CORRUPTED;
     return -1;
   }
 
@@ -241,17 +322,19 @@ static int tdUpdateKVStoreHeader(int fd, char *fname, SStoreInfo *pInfo) {
 
   if (lseek(fd, 0, SEEK_SET) < 0) {
     uError("failed to lseek file %s since %s", fname, strerror(errno));
-    return TAOS_SYSTEM_ERROR(errno);
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    return -1;
   }
 
   tdEncodeStoreInfo(buf, pInfo);
   taosCalcChecksumAppend(0, (uint8_t *)buf, TD_KVSTORE_HEADER_SIZE);
   if (twrite(fd, buf, TD_KVSTORE_HEADER_SIZE) < TD_KVSTORE_HEADER_SIZE) {
-    uError("failed to write file %s %d bytes since %s", fname, TD_KVSTORE_HEADER_SIZE, strerror(errno));
-    return TAOS_SYSTEM_ERROR(errno);
+    uError("failed to write %d bytes to file %s since %s", TD_KVSTORE_HEADER_SIZE, fname, strerror(errno));
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    return -1;
   }
 
-  return TSDB_CODE_SUCCESS;
+  return 0;
 }
 
 static int tdInitKVStoreHeader(int fd, char *fname) {
@@ -283,7 +366,10 @@ static SKVStore *tdNewKVStore(char *fname, iterFunc iFunc, afterFunc aFunc, void
   if (pStore == NULL) goto _err;
 
   pStore->fname = strdup(fname);
-  if (pStore->map == NULL) goto _err;
+  if (pStore->map == NULL) {
+    terrno = TSDB_CODE_COM_OUT_OF_MEMORY;
+    goto _err;
+  }
 
   pStore->fsnap = tdGetKVStoreSnapshotFname(fname);
   if (pStore->fsnap == NULL) goto _err;
@@ -306,7 +392,6 @@ static SKVStore *tdNewKVStore(char *fname, iterFunc iFunc, afterFunc aFunc, void
   return pStore;
 
 _err:
-  terrno = TSDB_CODE_COM_OUT_OF_MEMORY;
   tdFreeKVStore(pStore);
   return NULL;
 }
@@ -343,13 +428,13 @@ static char *tdGetKVStoreNewFname(char *fdata) {
   return fname;
 }
 
-// static void *tdEncodeKVRecord(void *buf, SKVRecord *pRecord) {
-//   buf = taosEncodeFixedU64(buf, pRecord->uid);
-//   buf = taosEncodeFixedI64(buf, pRecord->offset);
-//   buf = taosEncodeFixedI32(buf, pRecord->size);
+static void *tdEncodeKVRecord(void *buf, SKVRecord *pRecord) {
+  buf = taosEncodeFixedU64(buf, pRecord->uid);
+  buf = taosEncodeFixedI64(buf, pRecord->offset);
+  buf = taosEncodeFixedI32(buf, pRecord->size);
 
-//   return buf;
-// }
+  return buf;
+}
 
 static void *tdDecodeKVRecord(void *buf, SKVRecord *pRecord) {
   buf = taosDecodeFixedU64(buf, &(pRecord->uid));
@@ -361,9 +446,12 @@ static void *tdDecodeKVRecord(void *buf, SKVRecord *pRecord) {
 
 static int tdRestoreKVStore(SKVStore *pStore) {
   char      tbuf[128] = "\0";
-  char *    buf = NULL;
+  void *    buf = NULL;
+  int       maxBufSize = 0;
   SKVRecord rInfo = {0};
 
+  ASSERT(TD_KVSTORE_HEADER_SIZE == lseek(pStore->fd, 0, SEEK_CUR));
+
   while (true) {
     ssize_t tsize = tread(pStore->fd, tbuf, sizeof(SKVRecord));
     if (tsize == 0) break;
@@ -375,17 +463,25 @@ static int tdRestoreKVStore(SKVStore *pStore) {
 
     char *pBuf = tdDecodeKVRecord(tbuf, &rInfo);
     ASSERT(POINTER_DISTANCE(pBuf, tbuf) == sizeof(SKVRecord));
+    ASSERT(rInfo.offset > 0 ? pStore->info.size == rInfo.offset : true);
 
     if (rInfo.offset < 0) {
       taosHashRemove(pStore->map, (void *)(&rInfo.uid), sizeof(rInfo.uid));
+      pStore->info.size += sizeof(SKVRecord);
+      pStore->info.nRecords--;
+      pStore->info.nDels++;
+      pStore->info.tombSize += (rInfo.size + sizeof(SKVRecord) + sizeof(SKVRecord));
     } else {
-      ASSERT(rInfo.offset > 0);
+      // TODO: add statistics
+      ASSERT(rInfo.offset > 0 && rInfo.size > 0);
       if (taosHashPut(pStore->map, (void *)(&rInfo.uid), sizeof(rInfo.uid), &rInfo, sizeof(rInfo)) < 0) {
         uError("failed to put record in KV store %s", pStore->fname);
         terrno = TSDB_CODE_COM_OUT_OF_MEMORY;
         goto _err;
       }
 
+      maxBufSize = MAX(maxBufSize, rInfo.size);
+
       if (lseek(pStore->fd, rInfo.size, SEEK_CUR) < 0) {
         uError("failed to lseek file %s since %s", pStore->fname, strerror(errno));
         terrno = TAOS_SYSTEM_ERROR(errno);
@@ -394,6 +490,13 @@ static int tdRestoreKVStore(SKVStore *pStore) {
     }
   }
 
+  buf = malloc(maxBufSize);
+  if (buf == NULL) {
+    uError("failed to allocate %d bytes in KV store %s", maxBufSize, pStore->fname);
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    goto _err;
+  }
+
   SHashMutableIterator *pIter = taosHashCreateIter(pStore->map);
   if (pIter == NULL) {
     uError("failed to create hash iter while opening KV store %s", pStore->fname);
@@ -418,11 +521,11 @@ static int tdRestoreKVStore(SKVStore *pStore) {
 
     if (!taosCheckChecksumWhole((uint8_t *)buf, pRecord->size)) {
       uError("file %s has checksum error, offset " PRId64 " size %d", pStore->fname, pRecord->offset, pRecord->size);
-      terrno = TSDB_CODE_TDB_FILE_CORRUPTED;
+      terrno = TSDB_CODE_COM_FILE_CORRUPTED;
       goto _err;
     }
 
-    if (pStore->iFunc) (*pStore->iFunc)(pStore->appH,buf, pRecord->size);
+    if (pStore->iFunc) (*pStore->iFunc)(pStore->appH, buf, pRecord->size);
   }
 
   taosHashDestroyIter(pIter);
@@ -430,9 +533,9 @@ static int tdRestoreKVStore(SKVStore *pStore) {
   if (pStore->aFunc) (*pStore->aFunc)(pStore->appH);
 
   tfree(buf);
-  return TSDB_CODE_SUCCESS;
+  return 0;
 
 _err:
   tfree(buf);
-  return terrno;
+  return -1;
 }
\ No newline at end of file