diff --git a/source/libs/tdb/src/db/tdb_mpool.c b/source/libs/tdb/src/db/tdb_mpool.c
index 9b67f405a92781b709cd237335a85120cf8b0b78..1b591a5c3fd84d7fab30bdd5b335a04fc99c2db2 100644
--- a/source/libs/tdb/src/db/tdb_mpool.c
+++ b/source/libs/tdb/src/db/tdb_mpool.c
@@ -15,7 +15,6 @@
 
 #include "tdb_mpool.h"
 
-static int         tdbGnrtFileID(const char *fname, uint8_t *fileid);
 static void        tdbMPoolRegFile(TDB_MPOOL *mp, TDB_MPFILE *mpf);
 static void        tdbMPoolUnregFile(TDB_MPOOL *mp, TDB_MPFILE *mpf);
 static TDB_MPFILE *tdbMPoolGetFile(TDB_MPOOL *mp, uint8_t *fileid);
@@ -230,22 +229,6 @@ int tdbMPoolFilePutPage(TDB_MPFILE *mpf, pgno_t pgno, void *addr) {
   return 0;
 }
 
-static int tdbGnrtFileID(const char *fname, uint8_t *fileid) {
-  struct stat statbuf;
-
-  if (stat(fname, &statbuf) < 0) {
-    return -1;
-  }
-
-  memset(fileid, 0, TDB_FILE_ID_LEN);
-
-  ((uint64_t *)fileid)[0] = (uint64_t)statbuf.st_ino;
-  ((uint64_t *)fileid)[1] = (uint64_t)statbuf.st_dev;
-  ((uint64_t *)fileid)[2] = rand();
-
-  return 0;
-}
-
 #define MPF_GET_BUCKETID(fileid)                   \
   ({                                               \
     uint64_t *tmp = (uint64_t *)fileid;            \
diff --git a/source/libs/tdb/src/db/tdb_util.c b/source/libs/tdb/src/db/tdb_util.c
new file mode 100644
index 0000000000000000000000000000000000000000..9a5df604c464f2decfd264e7cc8dc0393bd18153
--- /dev/null
+++ b/source/libs/tdb/src/db/tdb_util.c
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "tdb_inc.h"
+
+int tdbGnrtFileID(const char *fname, uint8_t *fileid) {
+  struct stat statbuf;
+
+  if (stat(fname, &statbuf) < 0) {
+    return -1;
+  }
+
+  memset(fileid, 0, TDB_FILE_ID_LEN);
+
+  ((uint64_t *)fileid)[0] = (uint64_t)statbuf.st_ino;
+  ((uint64_t *)fileid)[1] = (uint64_t)statbuf.st_dev;
+  ((uint64_t *)fileid)[2] = rand();
+
+  return 0;
+}
+
diff --git a/source/libs/tdb/src/inc/tdb_btree.h b/source/libs/tdb/src/inc/tdb_btree.h
new file mode 100644
index 0000000000000000000000000000000000000000..a593c3b4e8d37623a10943c9fecf8086c58fd4d2
--- /dev/null
+++ b/source/libs/tdb/src/inc/tdb_btree.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _TDB_BTREE_H_
+#define _TDB_BTREE_H_
+
+#include "tdb_inc.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct SBTree {
+  pgno_t root; // root page number
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /*_TDB_BTREE_H_*/
\ No newline at end of file
diff --git a/source/libs/tdb/src/inc/tdb_inc.h b/source/libs/tdb/src/inc/tdb_inc.h
index 885191477cfd3e760959a4f81d1dce7f5ba4475e..9e13f779e721af1ea65f99200a8a64f835310068 100644
--- a/source/libs/tdb/src/inc/tdb_inc.h
+++ b/source/libs/tdb/src/inc/tdb_inc.h
@@ -51,6 +51,9 @@ typedef int32_t pgsize_t;
 // tdb_log
 #define tdbError(var)
 
+// tdb util
+int tdbGnrtFileID(const char *fname, uint8_t *fileid);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/libs/tdb/src/inc/tdb_page.h b/source/libs/tdb/src/inc/tdb_page.h
new file mode 100644
index 0000000000000000000000000000000000000000..42981a5e8b90d6b68a51a4fd1879e3b655f85fc1
--- /dev/null
+++ b/source/libs/tdb/src/inc/tdb_page.h
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _TDB_PAGE_H_
+#define _TDB_PAGE_H_
+
+#include "tdb_inc.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Page header
+typedef struct {
+  uint32_t magic;
+  pgno_t   pgno;   // current page number
+  pgno_t   npgno;  // next page number
+  pgno_t   ppgno;  // prev page number
+} SPgHdr;
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /*_TDB_PAGE_H_*/
\ No newline at end of file