diff --git a/source/dnode/vnode/src/inc/vnodeInt.h b/source/dnode/vnode/src/inc/vnodeInt.h
index 12659ed0ed..33f762a33b 100644
--- a/source/dnode/vnode/src/inc/vnodeInt.h
+++ b/source/dnode/vnode/src/inc/vnodeInt.h
@@ -76,7 +76,6 @@ typedef struct SRSmaSnapReader    SRSmaSnapReader;
 typedef struct SRSmaSnapWriter    SRSmaSnapWriter;
 typedef struct SSnapDataHdr       SSnapDataHdr;
 typedef struct SCommitInfo        SCommitInfo;
-typedef struct SCompactInfo       SCompactInfo;
 
 #define VNODE_META_DIR  "meta"
 #define VNODE_TSDB_DIR  "tsdb"
@@ -428,13 +427,10 @@ struct SCommitInfo {
   SVnodeInfo info;
   SVnode*    pVnode;
   TXN*       txn;
-};
-struct SCompactInfo {
-  SVnodeInfo info;
-  SVnode*    pVnode;
-  TXN*       txn;
-};
 
+  // APIs
+  int32_t (*commitFn)(STsdb* pTsdb, SCommitInfo* pInfo);
+};
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/dnode/vnode/src/tsdb/tsdbCompact.c b/source/dnode/vnode/src/tsdb/tsdbCompact.c
index 7b64776187..244fa1c017 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCompact.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCompact.c
@@ -15,23 +15,26 @@
 
 #include "tsdb.h"
 
-// typedef struct {
-// } SMemDIter;
+typedef struct {
+} SMemDIter;
 
 typedef struct {
-  SArray    *aBlockIdx;  // SArray<SBlockIdx>
-  SMapData   mDataBlk;   // SMapData<SDataBlk>
-  SBlockData bData;
-  int32_t    iBlockIdx;
-  int32_t    iDataBlk;
-  int32_t    iRow;
+  SDataFReader *pReader;
+  SArray       *aBlockIdx;  // SArray<SBlockIdx>
+  SMapData      mDataBlk;   // SMapData<SDataBlk>
+  SBlockData    bData;
+  int32_t       iBlockIdx;
+  int32_t       iDataBlk;
+  int32_t       iRow;
 } SDataDIter;
 
 typedef struct {
-  SArray    *aSttBlk;  // SArray<SSttBlk>
-  SBlockData bData;
-  int32_t    iSttBlk;
-  int32_t    iRow;
+  SDataFReader *pReader;
+  int32_t       iStt;
+  SArray       *aSttBlk;  // SArray<SSttBlk>
+  SBlockData    bData;
+  int32_t       iSttBlk;
+  int32_t       iRow;
 } SSttDIter;
 
 typedef struct {
@@ -53,11 +56,66 @@ typedef struct {
 #define TSDB_FLG_DEEP_COMPACT 0x1
 
 // ITER =========================
-static int32_t tsdbDataIterOpen(STsdbDataIter *pIter) {
+static int32_t tsdbMemDIterOpen(STsdbDataIter **ppIter) {
   int32_t code = 0;
   int32_t lino = 0;
+
+  STsdbDataIter *pIter = (STsdbDataIter *)taosMemoryCalloc(1, sizeof(*pIter) + sizeof(SMemDIter));
+  if (pIter == NULL) {
+    code = TSDB_CODE_OUT_OF_MEMORY;
+    goto _exit;
+  }
+
   // TODO
+
 _exit:
+  if (code) {
+    *ppIter = NULL;
+  } else {
+    *ppIter = pIter;
+  }
+  return code;
+}
+
+static int32_t tsdbDataDIterOpen(SDataFReader *pReader, STsdbDataIter **ppIter) {
+  int32_t code = 0;
+  int32_t lino = 0;
+
+  STsdbDataIter *pIter = (STsdbDataIter *)taosMemoryCalloc(1, sizeof(*pIter) + sizeof(SDataDIter));
+  if (NULL == pIter) {
+    code = TSDB_CODE_OUT_OF_MEMORY;
+    goto _exit;
+  }
+
+  // TODO
+
+_exit:
+  if (code) {
+    *ppIter = NULL;
+  } else {
+    *ppIter = pIter;
+  }
+  return code;
+}
+
+static int32_t tsdbSttDIterOpen(SDataFReader *pReader, STsdbDataIter **ppIter) {
+  int32_t code = 0;
+  int32_t lino = 0;
+
+  STsdbDataIter *pIter = (STsdbDataIter *)taosMemoryCalloc(1, sizeof(*pIter) + sizeof(SSttDIter));
+  if (pIter == NULL) {
+    code = TSDB_CODE_OUT_OF_MEMORY;
+    goto _exit;
+  }
+
+  // TODO
+
+_exit:
+  if (code) {
+    *ppIter = NULL;
+  } else {
+    *ppIter = pIter;
+  }
   return code;
 }
 
diff --git a/source/dnode/vnode/src/vnd/vnodeCompact.c b/source/dnode/vnode/src/vnd/vnodeCompact.c
index 26c1ddd9e5..fa45cb9b51 100644
--- a/source/dnode/vnode/src/vnd/vnodeCompact.c
+++ b/source/dnode/vnode/src/vnd/vnodeCompact.c
@@ -17,9 +17,7 @@
 
 extern void vnodePrepareCommit(SVnode *pVnode);
 
-#define vnodePrepareCompact vnodePrepareCommit
-
-static int32_t vnodeCompactImpl(SCompactInfo *pInfo) {
+static int32_t vnodeCompactImpl(SCommitInfo *pInfo) {
   int32_t code = 0;
 
   // TODO
@@ -30,7 +28,7 @@ static int32_t vnodeCompactImpl(SCompactInfo *pInfo) {
 static int32_t vnodeCompactTask(void *param) {
   int32_t code = 0;
 
-  SCompactInfo *pInfo = (SCompactInfo *)param;
+  SCommitInfo *pInfo = (SCommitInfo *)param;
 
   // compact
   vnodeCompactImpl(pInfo);
@@ -46,10 +44,10 @@ int32_t vnodeAsyncCompact(SVnode *pVnode) {
   int32_t code = 0;
 
   // prepare
-  vnodePrepareCompact(pVnode);
+  vnodePrepareCommit(pVnode);
 
   // schedule compact task
-  SCompactInfo *pInfo = taosMemoryCalloc(1, sizeof(*pInfo));
+  SCommitInfo *pInfo = taosMemoryCalloc(1, sizeof(*pInfo));
   if (NULL == pInfo) {
     code = TSDB_CODE_OUT_OF_MEMORY;
     goto _exit;