diff --git a/source/libs/tdb/inc/tdb.h b/source/libs/tdb/inc/tdb.h
index 443c02ff32..85af417e76 100644
--- a/source/libs/tdb/inc/tdb.h
+++ b/source/libs/tdb/inc/tdb.h
@@ -29,29 +29,32 @@ typedef struct STDbCurosr TDBC;
 typedef int32_t pgsz_t;
 typedef int32_t cachesz_t;
 
+typedef int (*TdbKeyCmprFn)(int keyLen1, const void *pKey1, int keyLen2, const void *pKey2);
+
 // TEVN
 int tdbEnvCreate(TENV **ppEnv, const char *rootDir);
 int tdbEnvOpen(TENV *ppEnv);
 int tdbEnvClose(TENV *pEnv);
 
-int tdbEnvBeginTxn(TENV *pEnv);
-int tdbEnvCommit(TENV *pEnv);
-
 int       tdbEnvSetCache(TENV *pEnv, pgsz_t pgSize, cachesz_t cacheSize);
 pgsz_t    tdbEnvGetPageSize(TENV *pEnv);
 cachesz_t tdbEnvGetCacheSize(TENV *pEnv);
 
+int tdbEnvBeginTxn(TENV *pEnv);
+int tdbEnvCommit(TENV *pEnv);
+
 // TDB
 int tdbCreate(TDB **ppDb);
-int tdbOpen(TDB **ppDb, const char *fname, const char *dbname, TENV *pEnv);
+int tdbOpen(TDB *pDb, const char *fname, const char *dbname, TENV *pEnv);
 int tdbClose(TDB *pDb);
 
 int tdbSetKeyLen(TDB *pDb, int klen);
 int tdbSetValLen(TDB *pDb, int vlen);
 int tdbSetDup(TDB *pDb, int dup);
-int tdbGetKeyLen(TDB *pDb, int *pklen);
-int tdbGetValLen(TDB *pDb, int *pvlen);
-int tdbGetDup(TDB *pDb, int *pdup);
+int tdbSetCmprFunc(TDB *pDb, TdbKeyCmprFn fn);
+int tdbGetKeyLen(TDB *pDb);
+int tdbGetValLen(TDB *pDb);
+int tdbGetDup(TDB *pDb);
 
 int tdbInsert(TDB *pDb, const void *pKey, int nKey, const void *pData, int nData);
 
diff --git a/source/libs/tdb/src/db/tdb.c b/source/libs/tdb/src/db/tdb.c
index b983ce43dd..714ea23317 100644
--- a/source/libs/tdb/src/db/tdb.c
+++ b/source/libs/tdb/src/db/tdb.c
@@ -16,9 +16,14 @@
 #include "tdbInt.h"
 
 struct STDb {
-  SBTree * pBt;      // current access method
-  SPgFile *pPgFile;  // backend page file this DB is using
-  TENV *   pEnv;     // TENV containing the DB
+  char *       dbname;   // dbname;
+  SBTree *     pBt;      // current access method (may extend)
+  SPgFile *    pPgFile;  // backend page file this DB is using
+  TENV *       pEnv;     // TENV containing the DB
+  int          klen;     // key length if know
+  int          vlen;     // value length if know
+  bool         dup;      // dup mode
+  TdbKeyCmprFn cFn;      // compare function
 };
 
 struct STDbCurosr {
@@ -28,13 +33,18 @@ struct STDbCurosr {
 int tdbCreate(TDB **ppDb) {
   TDB *pDb;
 
+  // create the handle
   pDb = (TDB *)calloc(1, sizeof(*pDb));
   if (pDb == NULL) {
     return -1;
   }
 
-  /* TODO */
+  pDb->klen = TDB_VARIANT_LEN;
+  pDb->vlen = TDB_VARIANT_LEN;
+  pDb->dup = false;
+  pDb->cFn = NULL /*TODO*/;
 
+  *ppDb = pDb;
   return 0;
 }
 
@@ -45,22 +55,14 @@ static int tdbDestroy(TDB *pDb) {
   return 0;
 }
 
-int tdbOpen(TDB **ppDb, const char *fname, const char *dbname, TENV *pEnv) {
-  TDB *     pDb;
+int tdbOpen(TDB *pDb, const char *fname, const char *dbname, TENV *pEnv) {
   int       ret;
   uint8_t   fileid[TDB_FILE_ID_LEN];
   SPgFile * pPgFile;
   SPgCache *pPgCache;
   SBTree *  pBt;
 
-  // Create DB if DB handle is not created yet
-  if (ppDb == NULL) {
-    if ((ret = tdbCreate(ppDb)) != 0) {
-      return -1;
-    }
-  }
-
-  pDb = *ppDb;
+  ASSERT(pDb != NULL);
 
   // Create a default ENV if pEnv is not set
   if (pEnv == NULL) {
@@ -107,4 +109,46 @@ int tdbOpen(TDB **ppDb, const char *fname, const char *dbname, TENV *pEnv) {
 int tdbClose(TDB *pDb) {
   if (pDb == NULL) return 0;
   return tdbDestroy(pDb);
+}
+
+int tdbSetKeyLen(TDB *pDb, int klen) {
+  // TODO: check `klen`
+  pDb->klen = klen;
+  return 0;
+}
+
+int tdbSetValLen(TDB *pDb, int vlen) {
+  // TODO: check `vlen`
+  pDb->vlen = vlen;
+  return 0;
+}
+
+int tdbSetDup(TDB *pDb, int dup) {
+  if (dup) {
+    pDb->dup = true;
+  } else {
+    pDb->dup = false;
+  }
+  return 0;
+}
+
+int tdbSetCmprFunc(TDB *pDb, TdbKeyCmprFn fn) {
+  if (fn == NULL) {
+    return -1;
+  } else {
+    pDb->cFn = fn;
+  }
+  return 0;
+}
+
+int tdbGetKeyLen(TDB *pDb) { return pDb->klen; }
+
+int tdbGetValLen(TDB *pDb) { return pDb->vlen; }
+
+int tdbGetDup(TDB *pDb) {
+  if (pDb->dup) {
+    return 1;
+  } else {
+    return 0;
+  }
 }
\ No newline at end of file
diff --git a/source/libs/tdb/src/inc/tdbInt.h b/source/libs/tdb/src/inc/tdbInt.h
index cafd1356cf..996d07b956 100644
--- a/source/libs/tdb/src/inc/tdbInt.h
+++ b/source/libs/tdb/src/inc/tdbInt.h
@@ -96,7 +96,7 @@ typedef TD_DLIST(SPgFile) SPgFileList;
     }                             \
   } while (0)
 
-#define TDB_VARIANT_LEN (int32_t) - 1
+#define TDB_VARIANT_LEN (int)-1
 
 // page payload format
 // <keyLen> + <valLen> + [key] + [value]
diff --git a/source/libs/tdb/test/tdbTest.cpp b/source/libs/tdb/test/tdbTest.cpp
index ccaddb4e14..065b83b2c2 100644
--- a/source/libs/tdb/test/tdbTest.cpp
+++ b/source/libs/tdb/test/tdbTest.cpp
@@ -19,12 +19,19 @@ TEST(tdb_test, simple_test) {
 
   GTEST_ASSERT_EQ(tdbEnvOpen(pEnv), 0);
 
-#if 0
+#if 1
   // DB
-  tdbOpen(&pDb1, "db.db", "db1", pEnv);
-  tdbOpen(&pDb2, "db.db", "db2", pEnv);
-  tdbOpen(&pDb3, "index.db", NULL, pEnv);
+  GTEST_ASSERT_EQ(tdbCreate(&pDb1), 0);
 
+  GTEST_ASSERT_EQ(tdbSetKeyLen(pDb1, 8), 0);
+
+  // GTEST_ASSERT_EQ(tdbSetValLen(pDb1, 3), 0);
+
+  // GTEST_ASSERT_EQ(tdbSetDup(pDb1, 3), 0);
+
+  GTEST_ASSERT_EQ(tdbOpen(pDb1, "db.db", "db1", pEnv), 0);
+
+#if 0
   // Insert
 
   // Query
@@ -32,10 +39,13 @@ TEST(tdb_test, simple_test) {
   // Delete
 
   // Query
+#endif
 
-  // Close
+  // GTEST_ASSERT_EQ(tdbOpen(&pDb2, "db.db", "db2", pEnv), 0);
+  // GTEST_ASSERT_EQ(tdbOpen(&pDb3, "index.db", NULL, pEnv), 0);
+  // tdbClose(pDb3);
+  // tdbClose(pDb2);
   tdbClose(pDb1);
-  tdbClose(pDb2);
 #endif
 
   tdbEnvClose(pEnv);