diff --git a/source/dnode/vnode/src/tsdb/dev/inc/tsdbDataFReaderWriter.h b/source/dnode/vnode/src/tsdb/dev/inc/tsdbDataFReaderWriter.h
index 1ebcbf387b125b0d09424f3f7cf4737584eaded9..565aca00b1d027b63d3d132ec6d683a35d61355a 100644
--- a/source/dnode/vnode/src/tsdb/dev/inc/tsdbDataFReaderWriter.h
+++ b/source/dnode/vnode/src/tsdb/dev/inc/tsdbDataFReaderWriter.h
@@ -30,6 +30,11 @@ typedef struct SDataFileReaderConfig SDataFileReaderConfig;
 typedef struct SDataFileWriter       SDataFileWriter;
 typedef struct SDataFileWriterConfig SDataFileWriterConfig;
 
+int32_t tsdbDataFileWriterOpen(const SDataFileWriterConfig *config, SDataFileWriter **ppWriter);
+int32_t tsdbDataFileWriterClose(SDataFileWriter *pWriter);
+int32_t tsdbDataFileWriteTSData(SDataFileWriter *pWriter, SBlockData *pBlockData);
+int32_t tsdbDataFileWriteTSDataBlock(SDataFileWriter *pWriter, SBlockData *pBlockData);
+
 struct SDataFileReaderConfig {
   STsdb *pTsdb;
   // TODO
diff --git a/source/dnode/vnode/src/tsdb/dev/inc/tsdbSttFReaderWriter.h b/source/dnode/vnode/src/tsdb/dev/inc/tsdbSttFReaderWriter.h
index 683c9e9e696e5e6b5a9c35091af52ad31bd871d1..7f6cea0abbdc7957ca4a7c8c5a3c9d2379eb61ea 100644
--- a/source/dnode/vnode/src/tsdb/dev/inc/tsdbSttFReaderWriter.h
+++ b/source/dnode/vnode/src/tsdb/dev/inc/tsdbSttFReaderWriter.h
@@ -22,7 +22,7 @@
 extern "C" {
 #endif
 
-// SSttFReader ==========================================
+// SSttFileReader ==========================================
 typedef struct SSttFSegReader       SSttFSegReader;
 typedef struct SSttFileReader       SSttFileReader;
 typedef struct SSttFileReaderConfig SSttFileReaderConfig;
@@ -50,7 +50,7 @@ struct SSttFileReaderConfig {
   // TODO
 };
 
-// SSttFWriter ==========================================
+// SSttFileWriter ==========================================
 typedef struct SSttFileWriter       SSttFileWriter;
 typedef struct SSttFileWriterConfig SSttFileWriterConfig;
 
diff --git a/source/dnode/vnode/src/tsdb/dev/tsdbDataFReaderWriter.c b/source/dnode/vnode/src/tsdb/dev/tsdbDataFReaderWriter.c
index bccd5ce97a5144ef5db25af71ee6b6bec8be6d5e..221106899eed2f96f5ee035a9948ec8aba92419d 100644
--- a/source/dnode/vnode/src/tsdb/dev/tsdbDataFReaderWriter.c
+++ b/source/dnode/vnode/src/tsdb/dev/tsdbDataFReaderWriter.c
@@ -23,4 +23,52 @@ struct SDataFileReader {
 // SDataFileWriter =============================================
 struct SDataFileWriter {
   // TODO
-};
\ No newline at end of file
+};
+
+int32_t tsdbDataFileWriterOpen(const SDataFileWriterConfig *config, SDataFileWriter **ppWriter) {
+  int32_t code = 0;
+  int32_t lino = 0;
+  int32_t vid = TD_VID(config->pTsdb->pVnode);
+// TODO
+_exit:
+  if (code) {
+    tsdbError("vgId:%d %s failed at line %d since %s", vid, __func__, lino, tstrerror(code));
+  }
+  return code;
+}
+
+int32_t tsdbDataFileWriterClose(SDataFileWriter *pWriter) {
+  int32_t code = 0;
+  int32_t lino = 0;
+  int32_t vid = 0;  // TODO: TD_VID(config->pTsdb->pVnode);
+// TODO
+_exit:
+  if (code) {
+    tsdbError("vgId:%d %s failed at line %d since %s", vid, __func__, lino, tstrerror(code));
+  }
+  return code;
+}
+
+int32_t tsdbDataFileWriteTSData(SDataFileWriter *pWriter, SBlockData *pBlockData) {
+  int32_t code = 0;
+  int32_t lino = 0;
+  int32_t vid = 0;  // TODO: TD_VID(config->pTsdb->pVnode);
+// TODO
+_exit:
+  if (code) {
+    tsdbError("vgId:%d %s failed at line %d since %s", vid, __func__, lino, tstrerror(code));
+  }
+  return code;
+}
+
+int32_t tsdbDataFileWriteTSDataBlock(SDataFileWriter *pWriter, SBlockData *pBlockData) {
+  int32_t code = 0;
+  int32_t lino = 0;
+  int32_t vid = 0;  // TODO: TD_VID(config->pTsdb->pVnode);
+// TODO
+_exit:
+  if (code) {
+    tsdbError("vgId:%d %s failed at line %d since %s", vid, __func__, lino, tstrerror(code));
+  }
+  return code;
+}
\ No newline at end of file
diff --git a/source/dnode/vnode/src/tsdb/dev/tsdbMerge.c b/source/dnode/vnode/src/tsdb/dev/tsdbMerge.c
index f8b972562faed23471736e11c52fc68dca935f91..823d29edb4312d26d4132f704d0047d7ee6c33af 100644
--- a/source/dnode/vnode/src/tsdb/dev/tsdbMerge.c
+++ b/source/dnode/vnode/src/tsdb/dev/tsdbMerge.c
@@ -197,9 +197,13 @@ static int32_t tsdbMergeFileSetBegin(SMerger *merger) {
       merger->ctx.level++;
 
       // open the reader
-      SSttFileReader *reader;
-      // code = tsdbSttFileReaderOpen(&fobj->f.stt, &reader);
-      // TSDB_CHECK_CODE(code, lino, _exit);
+      SSttFileReader      *reader;
+      SSttFileReaderConfig config = {
+          .pTsdb = merger->tsdb,
+          // TODO
+      };
+      code = tsdbSttFReaderOpen(&config, &reader);
+      TSDB_CHECK_CODE(code, lino, _exit);
 
       code = TARRAY2_APPEND(&merger->sttReaderArr, reader);
       TSDB_CHECK_CODE(code, lino, _exit);
@@ -216,34 +220,50 @@ static int32_t tsdbMergeFileSetBegin(SMerger *merger) {
   }
 
   // open stt file writer
-  SSttFileWriterConfig config = {
-      .pTsdb = merger->tsdb,
-      .maxRow = merger->maxRow,
-      .szPage = merger->szPage,
-      .cmprAlg = merger->cmprAlg,
-      .pSkmTb = &merger->skmTb,
-      .pSkmRow = &merger->skmRow,
-      .aBuf = merger->aBuf,
-  };
   if (lvl) {
-    config.file = fobj->f;
+    SSttFileWriterConfig config = {
+        .pTsdb = merger->tsdb,
+        .maxRow = merger->maxRow,
+        .szPage = merger->szPage,
+        .cmprAlg = merger->cmprAlg,
+        .pSkmTb = &merger->skmTb,
+        .pSkmRow = &merger->skmRow,
+        .aBuf = merger->aBuf,
+        .file = fobj->f,
+    };
+    code = tsdbSttFWriterOpen(&config, &merger->sttWriter);
+    TSDB_CHECK_CODE(code, lino, _exit);
   } else {
-    config.file = (STFile){
-        .type = TSDB_FTYPE_STT,
-        .did = {.level = 0, .id = 0},
-        .fid = fset->fid,
-        .cid = merger->cid,
-        .size = 0,
-        .stt = {.level = merger->ctx.level, .nseg = 0},
+    SSttFileWriterConfig config = {
+        .pTsdb = merger->tsdb,
+        .maxRow = merger->maxRow,
+        .szPage = merger->szPage,
+        .cmprAlg = merger->cmprAlg,
+        .pSkmTb = &merger->skmTb,
+        .pSkmRow = &merger->skmRow,
+        .aBuf = merger->aBuf,
+        .file =
+            (STFile){
+                .type = TSDB_FTYPE_STT,
+                .did = {.level = 0, .id = 0},
+                .fid = fset->fid,
+                .cid = merger->cid,
+                .size = 0,
+                .stt = {.level = merger->ctx.level, .nseg = 0},
+            },
     };
+    code = tsdbSttFWriterOpen(&config, &merger->sttWriter);
+    TSDB_CHECK_CODE(code, lino, _exit);
   }
-  code = tsdbSttFWriterOpen(&config, &merger->sttWriter);
-  TSDB_CHECK_CODE(code, lino, _exit);
 
   // open data file writer
   if (merger->ctx.toData) {
-    // code = tsdbDataFWriterOpen();
-    // TSDB_CHECK_CODE(code, lino, _exit);
+    SDataFileWriterConfig config = {
+        .pTsdb = merger->tsdb,
+        // TODO
+    };
+    code = tsdbDataFileWriterOpen(&config, &merger->dataWriter);
+    TSDB_CHECK_CODE(code, lino, _exit);
   }
 
 _exit: