diff --git a/source/libs/tdb/src/db/tdbBtree.c b/source/libs/tdb/src/db/tdbBtree.c
index fc27e88cf1..f4e1621742 100644
--- a/source/libs/tdb/src/db/tdbBtree.c
+++ b/source/libs/tdb/src/db/tdbBtree.c
@@ -29,15 +29,15 @@ struct SBTree {
   int            minLocal;
   int            maxLeaf;
   int            minLeaf;
-  u8            *pTmp;
+  void          *pBuf;
 };
 
 #define TDB_BTREE_PAGE_COMMON_HDR u8 flags;
 
-#define TDB_BTREE_PAGE_GET_FLAGS(PAGE) (PAGE)->pData[0]
+#define TDB_BTREE_PAGE_GET_FLAGS(PAGE)        (PAGE)->pData[0]
 #define TDB_BTREE_PAGE_SET_FLAGS(PAGE, flags) ((PAGE)->pData[0] = (flags))
-#define TDB_BTREE_PAGE_IS_ROOT(PAGE) (TDB_BTREE_PAGE_GET_FLAGS(PAGE) & TDB_BTREE_ROOT)
-#define TDB_BTREE_PAGE_IS_LEAF(PAGE) (TDB_BTREE_PAGE_GET_FLAGS(PAGE) & TDB_BTREE_LEAF)
+#define TDB_BTREE_PAGE_IS_ROOT(PAGE)          (TDB_BTREE_PAGE_GET_FLAGS(PAGE) & TDB_BTREE_ROOT)
+#define TDB_BTREE_PAGE_IS_LEAF(PAGE)          (TDB_BTREE_PAGE_GET_FLAGS(PAGE) & TDB_BTREE_LEAF)
 #define TDB_BTREE_ASSERT_FLAG(flags)                                                 \
   ASSERT(TDB_FLAG_IS(flags, TDB_BTREE_ROOT) || TDB_FLAG_IS(flags, TDB_BTREE_LEAF) || \
          TDB_FLAG_IS(flags, TDB_BTREE_ROOT | TDB_BTREE_LEAF) || TDB_FLAG_IS(flags, 0))
@@ -101,7 +101,7 @@ int tdbBtreeOpen(int keyLen, int valLen, SPager *pPager, FKeyComparator kcmpr, S
   // pBt->kcmpr
   pBt->kcmpr = kcmpr ? kcmpr : tdbDefaultKeyCmprFn;
   // pBt->pageSize
-  pBt->pageSize = tdbPagerGetPageSize(pPager);
+  pBt->pageSize = pPager->pageSize;
   // pBt->maxLocal
   pBt->maxLocal = tdbPageCapacity(pBt->pageSize, sizeof(SIntHdr)) / 4;
   // pBt->minLocal: Should not be allowed smaller than 15, which is [nPayload][nKey][nData]
@@ -127,132 +127,144 @@ int tdbBtreeClose(SBTree *pBt) {
   return 0;
 }
 
-int tdbBtCursorInsert(SBTC *pBtc, const void *pKey, int kLen, const void *pVal, int vLen) {
-  int     ret;
-  int     idx;
-  SPager *pPager;
-  SCell  *pCell;
-  int     szCell;
-  int     cret;
-  SBTree *pBt;
+int tdbBtreeInsert(SBTree *pBt, const void *pKey, int kLen, const void *pVal, int vLen) {
+  SBTC   btc;
+  SCell *pCell;
+  void  *pBuf;
+  int    szCell;
+  int    szBuf;
+  int    ret;
+  int    idx;
+  int    c;
 
-  ret = tdbBtcMoveTo(pBtc, pKey, kLen, &cret);
+  tdbBtcOpen(&btc, pBt);
+
+  // move to the position to insert
+  ret = tdbBtcMoveTo(&btc, pKey, kLen, &c);
   if (ret < 0) {
-    // TODO: handle error
+    tdbBtcClose(&btc);
+    ASSERT(0);
     return -1;
   }
 
-  if (pBtc->idx == -1) {
-    ASSERT(TDB_PAGE_TOTAL_CELLS(pBtc->pPage) == 0);
+  if (btc.idx == -1) {
     idx = 0;
   } else {
-    if (cret > 0) {
-      idx = pBtc->idx + 1;
-    } else if (cret < 0) {
-      idx = pBtc->idx;
+    if (c > 0) {
+      idx = btc.idx + 1;
+    } else if (c < 0) {
+      idx = btc.idx;
     } else {
-      /* TODO */
+      // TDB does NOT allow same key
+      tdbBtcClose(&btc);
       ASSERT(0);
-    }
-  }
-
-  // TODO: refact code here
-  pBt = pBtc->pBt;
-  if (!pBt->pTmp) {
-    pBt->pTmp = (u8 *)tdbOsMalloc(pBt->pageSize);
-    if (pBt->pTmp == NULL) {
       return -1;
     }
   }
 
-  pCell = pBt->pTmp;
+  // make sure enough space to hold the cell
+  szBuf = kLen + vLen + 14;
+  pBuf = TDB_REALLOC(pBt->pBuf, pBt->pageSize > szBuf ? szBuf : pBt->pageSize);
+  if (pBuf == NULL) {
+    tdbBtcClose(&btc);
+    ASSERT(0);
+    return -1;
+  }
+  pBt->pBuf = pBuf;
+  pCell = (SCell *)pBt->pBuf;
 
-  // Encode the cell
-  ret = tdbBtreeEncodeCell(pBtc->pPage, pKey, kLen, pVal, vLen, pCell, &szCell);
+  // encode cell
+  ret = tdbBtreeEncodeCell(btc.pPage, pKey, kLen, pVal, vLen, pCell, &szCell);
   if (ret < 0) {
+    tdbBtcClose(&btc);
+    ASSERT(0);
     return -1;
   }
 
-  // Insert the cell to the index
-  ret = tdbPageInsertCell(pBtc->pPage, idx, pCell, szCell, 0);
+  // mark the page dirty
+  ret = tdbPagerWrite(pBt->pPager, btc.pPage);
   if (ret < 0) {
+    tdbBtcClose(&btc);
+    ASSERT(0);
     return -1;
   }
 
-  // If page is overflow, balance the tree
-  if (pBtc->pPage->nOverflow > 0) {
-    ret = tdbBtreeBalance(pBtc);
+  // insert the cell
+  ret = tdbPageInsertCell(btc.pPage, idx, pCell, szCell, 0);
+  if (ret < 0) {
+    tdbBtcClose(&btc);
+    ASSERT(0);
+    return -1;
+  }
+
+  // check if need balance
+  if (btc.pPage->nOverflow > 0) {
+    ret = tdbBtreeBalance(&btc);
     if (ret < 0) {
+      tdbBtcClose(&btc);
+      ASSERT(0);
       return -1;
     }
   }
 
+  tdbBtcClose(&btc);
+
   return 0;
 }
 
 int tdbBtreeGet(SBTree *pBt, const void *pKey, int kLen, void **ppVal, int *vLen) {
-  SBTC         btc;
-  SCell       *pCell;
-  int          cret;
-  void        *pVal;
-  SCellDecoder cd;
-
-  tdbBtcOpen(&btc, pBt);
-
-  tdbBtcMoveTo(&btc, pKey, kLen, &cret);
-
-  if (cret) {
-    return cret;
-  }
-
-  pCell = tdbPageGetCell(btc.pPage, btc.idx);
-  tdbBtreeDecodeCell(btc.pPage, pCell, &cd);
-
-  *vLen = cd.vLen;
-  pVal = TDB_REALLOC(*ppVal, *vLen);
-  if (pVal == NULL) {
-    return -1;
-  }
-
-  *ppVal = pVal;
-  memcpy(*ppVal, cd.pVal, cd.vLen);
-  return 0;
+  return tdbBtreePGet(pBt, pKey, kLen, NULL, NULL, ppVal, vLen);
 }
 
 int tdbBtreePGet(SBTree *pBt, const void *pKey, int kLen, void **ppKey, int *pkLen, void **ppVal, int *vLen) {
   SBTC         btc;
   SCell       *pCell;
   int          cret;
-  void        *pTKey;
-  void        *pTVal;
+  int          ret;
+  void        *pTKey = NULL;
+  void        *pTVal = NULL;
   SCellDecoder cd;
 
   tdbBtcOpen(&btc, pBt);
 
-  tdbBtcMoveTo(&btc, pKey, kLen, &cret);
+  ret = tdbBtcMoveTo(&btc, pKey, kLen, &cret);
+  if (ret < 0) {
+    tdbBtcClose(&btc);
+    ASSERT(0);
+  }
+
   if (cret) {
-    return cret;
+    tdbBtcClose(&btc);
+    return -1;
   }
 
   pCell = tdbPageGetCell(btc.pPage, btc.idx);
   tdbBtreeDecodeCell(btc.pPage, pCell, &cd);
 
-  pTKey = TDB_REALLOC(*ppKey, cd.kLen);
-  pTVal = TDB_REALLOC(*ppVal, cd.vLen);
-
-  if (pTKey == NULL || pTVal == NULL) {
-    TDB_FREE(pTKey);
-    TDB_FREE(pTVal);
+  if (ppKey) {
+    pTKey = TDB_REALLOC(*ppKey, cd.kLen);
+    if (pTKey == NULL) {
+      tdbBtcClose(&btc);
+      ASSERT(0);
+      return -1;
+    }
+    *ppKey = pTKey;
+    *pkLen = cd.kLen;
+    memcpy(*ppKey, cd.pKey, cd.kLen);
   }
 
-  *ppKey = pTKey;
+  pTVal = TDB_REALLOC(*ppVal, cd.vLen);
+  if (pTVal == NULL) {
+    tdbBtcClose(&btc);
+    ASSERT(0);
+    return -1;
+  }
   *ppVal = pTVal;
-  *pkLen = cd.kLen;
   *vLen = cd.vLen;
-
-  memcpy(*ppKey, cd.pKey, cd.kLen);
   memcpy(*ppVal, cd.pVal, cd.vLen);
 
+  tdbBtcClose(&btc);
+
   return 0;
 }
 
@@ -300,7 +312,8 @@ static int tdbBtreeOpenImpl(SBTree *pBt) {
     return -1;
   }
 
-  // TODO: Unref the page
+  // TODO: here still has problem
+  tdbPagerReturnPage(pBt->pPager, pPage);
 
   ASSERT(pgno != 0);
   pBt->root = pgno;
@@ -371,17 +384,7 @@ static int tdbBtreeZeroPage(SPage *pPage, void *arg) {
   return 0;
 }
 
-#ifndef TDB_BTREE_BALANCE
-typedef struct {
-  SBTree *pBt;
-  SPage  *pParent;
-  int     idx;
-  i8      nOld;
-  SPage  *pOldPages[3];
-  i8      nNewPages;
-  SPage  *pNewPages[5];
-} SBtreeBalanceHelper;
-
+// TDB_BTREE_BALANCE =====================
 static int tdbBtreeBalanceDeeper(SBTree *pBt, SPage *pRoot, SPage **ppChild) {
   SPager           *pPager;
   SPage            *pChild;
@@ -408,6 +411,13 @@ static int tdbBtreeBalanceDeeper(SBTree *pBt, SPage *pRoot, SPage **ppChild) {
     ((SIntHdr *)pChild->pData)->pgno = ((SIntHdr *)(pRoot->pData))->pgno;
   }
 
+  ret = tdbPagerWrite(pPager, pChild);
+  if (ret < 0) {
+    // TODO
+    ASSERT(0);
+    return 0;
+  }
+
   // Copy the root page content to the child page
   tdbPageCopy(pRoot, pChild);
 
@@ -472,6 +482,13 @@ static int tdbBtreeBalanceNonRoot(SBTree *pBt, SPage *pParent, int idx) {
         ASSERT(0);
         return -1;
       }
+
+      ret = tdbPagerWrite(pBt->pPager, pOlds[i]);
+      if (ret < 0) {
+        // TODO
+        ASSERT(0);
+        return -1;
+      }
     }
     // copy the parent key out if child pages are not leaf page
     childNotLeaf = !TDB_BTREE_PAGE_IS_LEAF(pOlds[0]);
@@ -492,6 +509,14 @@ static int tdbBtreeBalanceNonRoot(SBTree *pBt, SPage *pParent, int idx) {
       }
       rPgno = ((SIntHdr *)pOlds[nOlds - 1]->pData)->pgno;
     }
+
+    ret = tdbPagerWrite(pBt->pPager, pParent);
+    if (ret < 0) {
+      // TODO
+      ASSERT(0);
+      return -1;
+    }
+
     // drop the cells on parent page
     for (int i = 0; i < nOlds; i++) {
       nCells = TDB_PAGE_TOTAL_CELLS(pParent);
@@ -619,6 +644,13 @@ static int tdbBtreeBalanceNonRoot(SBTree *pBt, SPage *pParent, int idx) {
         if (ret < 0) {
           ASSERT(0);
         }
+
+        ret = tdbPagerWrite(pBt->pPager, pNews[iNew]);
+        if (ret < 0) {
+          // TODO
+          ASSERT(0);
+          return -1;
+        }
       }
     }
 
@@ -732,14 +764,24 @@ static int tdbBtreeBalanceNonRoot(SBTree *pBt, SPage *pParent, int idx) {
     }
   }
 
+  // TODO: here is not corrent for drop case
+  for (int i = 0; i < nNews; i++) {
+    if (i < nOlds) {
+      tdbPagerReturnPage(pBt->pPager, pOlds[i]);
+    } else {
+      tdbPagerReturnPage(pBt->pPager, pNews[i]);
+    }
+  }
+
   return 0;
 }
 
 static int tdbBtreeBalance(SBTC *pBtc) {
   int    iPage;
+  int    ret;
+  int    nFree;
   SPage *pParent;
   SPage *pPage;
-  int    ret;
   u8     flags;
   u8     leaf;
   u8     root;
@@ -750,10 +792,11 @@ static int tdbBtreeBalance(SBTC *pBtc) {
     pPage = pBtc->pPage;
     leaf = TDB_BTREE_PAGE_IS_LEAF(pPage);
     root = TDB_BTREE_PAGE_IS_ROOT(pPage);
+    nFree = TDB_PAGE_FREE_SIZE(pPage);
 
     // when the page is not overflow and not too empty, the balance work
     // is finished. Just break out the balance loop.
-    if (pPage->nOverflow == 0 /* TODO: && pPage->nFree <= */) {
+    if (pPage->nOverflow == 0 && nFree < TDB_PAGE_USABLE_SIZE(pPage) * 2 / 3) {
       break;
     }
 
@@ -781,6 +824,8 @@ static int tdbBtreeBalance(SBTC *pBtc) {
         return -1;
       }
 
+      tdbPagerReturnPage(pBtc->pBt->pPager, pBtc->pPage);
+
       pBtc->iPage--;
       pBtc->pPage = pBtc->pgStack[pBtc->iPage];
     }
@@ -788,7 +833,7 @@ static int tdbBtreeBalance(SBTC *pBtc) {
 
   return 0;
 }
-#endif
+// TDB_BTREE_BALANCE
 
 // TDB_BTREE_CELL =====================
 static int tdbBtreeEncodePayload(SPage *pPage, SCell *pCell, int nHeader, const void *pKey, int kLen, const void *pVal,
@@ -1028,12 +1073,11 @@ int tdbBtcMoveToFirst(SBTC *pBtc) {
 
     // move upward
     for (;;) {
-      if (pBtc->iPage == 0) {
+      if (pBtc->iPage == iPage) {
         pBtc->idx = 0;
         break;
       }
 
-      if (pBtc->iPage < iPage) break;
       tdbBtcMoveUpward(pBtc);
     }
   }
@@ -1056,6 +1100,7 @@ int tdbBtcMoveToFirst(SBTC *pBtc) {
 
 int tdbBtcMoveToLast(SBTC *pBtc) {
   int     ret;
+  int     nCells;
   SBTree *pBt;
   SPager *pPager;
   SPgno   pgno;
@@ -1071,27 +1116,56 @@ int tdbBtcMoveToLast(SBTC *pBtc) {
       return -1;
     }
 
+    nCells = TDB_PAGE_TOTAL_CELLS(pBtc->pPage);
     pBtc->iPage = 0;
+    if (nCells > 0) {
+      pBtc->idx = TDB_BTREE_PAGE_IS_LEAF(pBtc->pPage) ? nCells - 1 : nCells;
+    } else {
+      // no data at all, point to an invalid position
+      ASSERT(TDB_BTREE_PAGE_IS_LEAF(pBtc->pPage));
+      pBtc->idx = -1;
+      return 0;
+    }
   } else {
-    // move from a position
-    ASSERT(0);
+    int iPage = 0;
+
+    // downward search
+    for (; iPage < pBtc->iPage; iPage++) {
+      ASSERT(!TDB_BTREE_PAGE_IS_LEAF(pBtc->pgStack[iPage]));
+      nCells = TDB_PAGE_TOTAL_CELLS(pBtc->pgStack[iPage]);
+      if (pBtc->idxStack[iPage] != nCells) break;
+    }
+
+    // move upward
+    for (;;) {
+      if (pBtc->iPage == iPage) {
+        if (TDB_BTREE_PAGE_IS_LEAF(pBtc->pPage)) {
+          pBtc->idx = TDB_PAGE_TOTAL_CELLS(pBtc->pPage) - 1;
+        } else {
+          pBtc->idx = TDB_PAGE_TOTAL_CELLS(pBtc->pPage);
+        }
+        break;
+      }
+
+      tdbBtcMoveUpward(pBtc);
+    }
   }
 
   // move downward
   for (;;) {
-    if (TDB_BTREE_PAGE_IS_LEAF(pBtc->pPage)) {
-      // TODO: handle empty case
-      ASSERT(TDB_PAGE_TOTAL_CELLS(pBtc->pPage) > 0);
-      pBtc->idx = TDB_PAGE_TOTAL_CELLS(pBtc->pPage) - 1;
-      break;
-    } else {
-      pBtc->idx = TDB_PAGE_TOTAL_CELLS(pBtc->pPage);
+    if (TDB_BTREE_PAGE_IS_LEAF(pBtc->pPage)) break;
 
-      ret = tdbBtcMoveDownward(pBtc);
-      if (ret < 0) {
-        ASSERT(0);
-        return -1;
-      }
+    ret = tdbBtcMoveDownward(pBtc);
+    if (ret < 0) {
+      ASSERT(0);
+      return -1;
+    }
+
+    nCells = TDB_PAGE_TOTAL_CELLS(pBtc->pPage);
+    if (TDB_BTREE_PAGE_IS_LEAF(pBtc->pPage)) {
+      pBtc->idx = nCells - 1;
+    } else {
+      pBtc->idx = nCells;
     }
   }
 
@@ -1104,6 +1178,7 @@ int tdbBtreeNext(SBTC *pBtc, void **ppKey, int *kLen, void **ppVal, int *vLen) {
   void        *pKey, *pVal;
   int          ret;
 
+  // current cursor points to an invalid position
   if (pBtc->idx < 0) {
     return -1;
   }
@@ -1134,12 +1209,17 @@ int tdbBtreeNext(SBTC *pBtc, void **ppKey, int *kLen, void **ppVal, int *vLen) {
   memcpy(pVal, cd.pVal, cd.vLen);
 
   ret = tdbBtcMoveToNext(pBtc);
+  if (ret < 0) {
+    ASSERT(0);
+    return -1;
+  }
 
   return 0;
 }
 
 static int tdbBtcMoveToNext(SBTC *pBtc) {
   int    nCells;
+  int    ret;
   SCell *pCell;
 
   ASSERT(TDB_BTREE_PAGE_IS_LEAF(pBtc->pPage));
@@ -1151,39 +1231,35 @@ static int tdbBtcMoveToNext(SBTC *pBtc) {
     return 0;
   }
 
-  if (pBtc->iPage == 0) {
-    pBtc->idx = -1;
-    return 0;
-  }
-
-  // Move upward
+  // move upward
   for (;;) {
-    tdbBtcMoveUpward(pBtc);
-    pBtc->idx++;
-
-    nCells = TDB_PAGE_TOTAL_CELLS(pBtc->pPage);
-    if (pBtc->idx <= nCells) {
-      break;
-    }
-
     if (pBtc->iPage == 0) {
       pBtc->idx = -1;
       return 0;
     }
-  }
 
-  // Move downward
-  for (;;) {
-    nCells = TDB_PAGE_TOTAL_CELLS(pBtc->pPage);
+    tdbBtcMoveUpward(pBtc);
+    pBtc->idx++;
 
-    tdbBtcMoveDownward(pBtc);
-    pBtc->idx = 0;
-
-    if (TDB_BTREE_PAGE_IS_LEAF(pBtc->pPage)) {
+    ASSERT(!TDB_BTREE_PAGE_IS_LEAF(pBtc->pPage));
+    if (pBtc->idx <= TDB_PAGE_TOTAL_CELLS(pBtc->pPage)) {
       break;
     }
   }
 
+  // move downward
+  for (;;) {
+    if (TDB_BTREE_PAGE_IS_LEAF(pBtc->pPage)) break;
+
+    ret = tdbBtcMoveDownward(pBtc);
+    if (ret < 0) {
+      ASSERT(0);
+      return -1;
+    }
+
+    pBtc->idx = 0;
+  }
+
   return 0;
 }
 
@@ -1230,91 +1306,145 @@ static int tdbBtcMoveUpward(SBTC *pBtc) {
 }
 
 static int tdbBtcMoveTo(SBTC *pBtc, const void *pKey, int kLen, int *pCRst) {
-  int     ret;
-  SBTree *pBt;
-  SPager *pPager;
+  int          ret;
+  int          nCells;
+  int          c;
+  SBTree      *pBt;
+  SCell       *pCell;
+  SPager      *pPager;
+  SCellDecoder cd = {0};
 
   pBt = pBtc->pBt;
   pPager = pBt->pPager;
 
   if (pBtc->iPage < 0) {
-    ASSERT(pBtc->iPage == -1);
-    ASSERT(pBtc->idx == -1);
-
-    // Move from the root
+    // move from a clear cursor
     ret = tdbPagerFetchPage(pPager, pBt->root, &(pBtc->pPage), tdbBtreeInitPage, pBt);
     if (ret < 0) {
+      // TODO
       ASSERT(0);
-      return -1;
-    }
-
-    pBtc->iPage = 0;
-
-    if (TDB_PAGE_TOTAL_CELLS(pBtc->pPage) == 0) {
-      // Current page is empty
-      // ASSERT(TDB_FLAG_IS(TDB_PAGE_FLAGS(pBtc->pPage), TDB_BTREE_ROOT | TDB_BTREE_LEAF));
       return 0;
     }
 
-    for (;;) {
-      int          lidx, ridx, midx, c, nCells;
-      SCell       *pCell;
-      SPage       *pPage;
-      SCellDecoder cd = {0};
+    pBtc->iPage = 0;
+    pBtc->idx = -1;
+    // for empty tree, just return with an invalid position
+    if (TDB_PAGE_TOTAL_CELLS(pBtc->pPage) == 0) return 0;
+  } else {
+    SPage *pPage;
+    int    idx;
+    int    iPage = 0;
 
-      pPage = pBtc->pPage;
+    // downward search
+    for (; iPage < pBtc->iPage; iPage++) {
+      pPage = pBtc->pgStack[iPage];
+      idx = pBtc->idxStack[iPage];
       nCells = TDB_PAGE_TOTAL_CELLS(pPage);
-      lidx = 0;
-      ridx = nCells - 1;
 
-      ASSERT(nCells > 0);
+      ASSERT(!TDB_BTREE_PAGE_IS_LEAF(pPage));
 
-      for (;;) {
-        if (lidx > ridx) break;
-
-        midx = (lidx + ridx) >> 1;
-
-        pCell = tdbPageGetCell(pPage, midx);
-        ret = tdbBtreeDecodeCell(pPage, pCell, &cd);
-        if (ret < 0) {
-          // TODO: handle error
-          ASSERT(0);
-          return -1;
-        }
-
-        // Compare the key values
+      // check if key <= current position
+      if (idx < nCells) {
+        pCell = tdbPageGetCell(pPage, idx);
+        tdbBtreeDecodeCell(pPage, pCell, &cd);
         c = pBt->kcmpr(pKey, kLen, cd.pKey, cd.kLen);
-        if (c < 0) {
-          /* input-key < cell-key */
-          ridx = midx - 1;
-        } else if (c > 0) {
-          /* input-key > cell-key */
-          lidx = midx + 1;
-        } else {
-          /* input-key == cell-key */
-          break;
-        }
+        if (c > 0) break;
       }
 
-      // Move downward or break
-      u8 leaf = TDB_BTREE_PAGE_IS_LEAF(pPage);
-      if (leaf) {
-        pBtc->idx = midx;
-        *pCRst = c;
-        break;
-      } else {
-        if (c <= 0) {
-          pBtc->idx = midx;
-        } else {
-          pBtc->idx = midx + 1;
-        }
-        tdbBtcMoveDownward(pBtc);
+      // check if key > current - 1 position
+      if (idx > 0) {
+        pCell = tdbPageGetCell(pPage, idx - 1);
+        tdbBtreeDecodeCell(pPage, pCell, &cd);
+        c = pBt->kcmpr(pKey, kLen, cd.pKey, cd.kLen);
+        if (c <= 0) break;
       }
     }
 
-  } else {
-    // TODO: Move the cursor from a some position instead of a clear state
-    ASSERT(0);
+    // move upward
+    for (;;) {
+      if (pBtc->iPage == iPage) break;
+      tdbBtcMoveUpward(pBtc);
+    }
+  }
+
+  // search downward to the leaf
+  for (;;) {
+    int    lidx, ridx, midx;
+    SPage *pPage;
+
+    pPage = pBtc->pPage;
+    nCells = TDB_PAGE_TOTAL_CELLS(pPage);
+    lidx = 0;
+    ridx = nCells - 1;
+
+    ASSERT(nCells > 0);
+    ASSERT(pBtc->idx == -1);
+
+    // compare first cell
+    midx = lidx;
+    pCell = tdbPageGetCell(pPage, midx);
+    tdbBtreeDecodeCell(pPage, pCell, &cd);
+    c = pBt->kcmpr(pKey, kLen, cd.pKey, cd.kLen);
+    if (c <= 0) {
+      ridx = lidx - 1;
+    } else {
+      lidx = lidx + 1;
+    }
+
+    // compare last cell
+    if (lidx <= ridx) {
+      midx = ridx;
+      pCell = tdbPageGetCell(pPage, midx);
+      tdbBtreeDecodeCell(pPage, pCell, &cd);
+      c = pBt->kcmpr(pKey, kLen, cd.pKey, cd.kLen);
+      if (c >= 0) {
+        lidx = ridx + 1;
+      } else {
+        ridx = ridx - 1;
+      }
+    }
+
+    // binary search
+    for (;;) {
+      if (lidx > ridx) break;
+
+      midx = (lidx + ridx) >> 1;
+
+      pCell = tdbPageGetCell(pPage, midx);
+      ret = tdbBtreeDecodeCell(pPage, pCell, &cd);
+      if (ret < 0) {
+        // TODO: handle error
+        ASSERT(0);
+        return -1;
+      }
+
+      // Compare the key values
+      c = pBt->kcmpr(pKey, kLen, cd.pKey, cd.kLen);
+      if (c < 0) {
+        // pKey < cd.pKey
+        ridx = midx - 1;
+      } else if (c > 0) {
+        // pKey > cd.pKey
+        lidx = midx + 1;
+      } else {
+        // pKey == cd.pKey
+        break;
+      }
+    }
+
+    // keep search downward or break
+    if (TDB_BTREE_PAGE_IS_LEAF(pPage)) {
+      pBtc->idx = midx;
+      *pCRst = c;
+      break;
+    } else {
+      if (c <= 0) {
+        pBtc->idx = midx;
+      } else {
+        pBtc->idx = midx + 1;
+      }
+      tdbBtcMoveDownward(pBtc);
+    }
   }
 
   return 0;
diff --git a/source/libs/tdb/src/db/tdbDb.c b/source/libs/tdb/src/db/tdbDb.c
index e41e41f72a..fe7b8c6d48 100644
--- a/source/libs/tdb/src/db/tdbDb.c
+++ b/source/libs/tdb/src/db/tdbDb.c
@@ -49,6 +49,8 @@ int tdbDbOpen(const char *fname, int keyLen, int valLen, FKeyComparator keyCmprF
     if (ret < 0) {
       return -1;
     }
+
+    tdbEnvAddPager(pEnv, pPager);
   }
 
   ASSERT(pPager != NULL);
@@ -74,22 +76,7 @@ int tdbDbDrop(TDB *pDb) {
 }
 
 int tdbDbInsert(TDB *pDb, const void *pKey, int keyLen, const void *pVal, int valLen) {
-  SBTC  btc;
-  SBTC *pCur;
-  int   ret;
-
-  pCur = &btc;
-  ret = tdbBtcOpen(pCur, pDb->pBt);
-  if (ret < 0) {
-    return -1;
-  }
-
-  ret = tdbBtCursorInsert(pCur, pKey, keyLen, pVal, valLen);
-  if (ret < 0) {
-    return -1;
-  }
-
-  return 0;
+  return tdbBtreeInsert(pDb->pBt, pKey, keyLen, pVal, valLen);
 }
 
 int tdbDbGet(TDB *pDb, const void *pKey, int kLen, void **ppVal, int *vLen) {
diff --git a/source/libs/tdb/src/db/tdbEnv.c b/source/libs/tdb/src/db/tdbEnv.c
index 4439147e09..06d37df653 100644
--- a/source/libs/tdb/src/db/tdbEnv.c
+++ b/source/libs/tdb/src/db/tdbEnv.c
@@ -19,6 +19,7 @@ int tdbEnvOpen(const char *rootDir, int pageSize, int cacheSize, TENV **ppEnv) {
   TENV *pEnv;
   int   dsize;
   int   zsize;
+  int   tsize;
   u8   *pPtr;
   int   ret;
 
@@ -53,6 +54,14 @@ int tdbEnvOpen(const char *rootDir, int pageSize, int cacheSize, TENV **ppEnv) {
     return -1;
   }
 
+  pEnv->nPgrHash = 8;
+  tsize = sizeof(SPager *) * pEnv->nPgrHash;
+  pEnv->pgrHash = TDB_REALLOC(pEnv->pgrHash, tsize);
+  if (pEnv->pgrHash == NULL) {
+    return -1;
+  }
+  memset(pEnv->pgrHash, 0, tsize);
+
   mkdir(rootDir, 0755);
 
   *ppEnv = pEnv;
@@ -64,7 +73,99 @@ int tdbEnvClose(TENV *pEnv) {
   return 0;
 }
 
+int tdbBegin(TENV *pEnv) {
+  SPager *pPager;
+  int     ret;
+
+  for (pPager = pEnv->pgrList; pPager; pPager = pPager->pNext) {
+    ret = tdbPagerBegin(pPager);
+    if (ret < 0) {
+      ASSERT(0);
+      return -1;
+    }
+  }
+
+  return 0;
+}
+
+int tdbCommit(TENV *pEnv) {
+  SPager *pPager;
+  int     ret;
+
+  for (pPager = pEnv->pgrList; pPager; pPager = pPager->pNext) {
+    ret = tdbPagerCommit(pPager);
+    if (ret < 0) {
+      ASSERT(0);
+      return -1;
+    }
+  }
+
+  return 0;
+}
+
+int tdbRollback(TENV *pEnv) {
+  ASSERT(0);
+  return 0;
+}
+
 SPager *tdbEnvGetPager(TENV *pEnv, const char *fname) {
-  // TODO
-  return NULL;
+  u32      hash;
+  SPager **ppPager;
+
+  hash = tdbCstringHash(fname);
+  ppPager = &pEnv->pgrHash[hash % pEnv->nPgrHash];
+  for (; *ppPager && (strcmp(fname, (*ppPager)->dbFileName) != 0); ppPager = &((*ppPager)->pHashNext)) {
+  }
+
+  return *ppPager;
+}
+
+void tdbEnvAddPager(TENV *pEnv, SPager *pPager) {
+  u32      hash;
+  SPager **ppPager;
+
+  // rehash if neccessary
+  if (pEnv->nPager + 1 > pEnv->nPgrHash) {
+    // TODO
+  }
+
+  // add to list
+  pPager->pNext = pEnv->pgrList;
+  pEnv->pgrList = pPager;
+
+  // add to hash
+  hash = tdbCstringHash(pPager->dbFileName);
+  ppPager = &pEnv->pgrHash[hash % pEnv->nPgrHash];
+  pPager->pHashNext = *ppPager;
+  *ppPager = pPager;
+
+  // increase the counter
+  pEnv->nPager++;
+}
+
+void tdbEnvRemovePager(TENV *pEnv, SPager *pPager) {
+  u32      hash;
+  SPager **ppPager;
+
+  // remove from the list
+  for (ppPager = &pEnv->pgrList; *ppPager && (*ppPager != pPager); ppPager = &((*ppPager)->pNext)) {
+  }
+  ASSERT(*ppPager == pPager);
+  *ppPager = pPager->pNext;
+
+  // remove from hash
+  hash = tdbCstringHash(pPager->dbFileName);
+  ppPager = &pEnv->pgrHash[hash % pEnv->nPgrHash];
+  for (; *ppPager && *ppPager != pPager; ppPager = &((*ppPager)->pHashNext)) {
+  }
+  ASSERT(*ppPager == pPager);
+  *ppPager = pPager->pNext;
+
+  // decrease the counter
+  pEnv->nPager--;
+
+  // rehash if necessary
+  if (pEnv->nPgrHash > 8 && pEnv->nPager < pEnv->nPgrHash / 2) {
+    // TODO
+  }
 }
\ No newline at end of file
diff --git a/source/libs/tdb/src/db/tdbPCache.c b/source/libs/tdb/src/db/tdbPCache.c
index 07c267a15c..d886cfd889 100644
--- a/source/libs/tdb/src/db/tdbPCache.c
+++ b/source/libs/tdb/src/db/tdbPCache.c
@@ -34,18 +34,6 @@ struct SPCache {
   })
 #define PAGE_IS_PINNED(pPage) ((pPage)->pLruNext == NULL)
 
-// For page ref
-#define TDB_INIT_PAGE_REF(pPage) ((pPage)->nRef = 0)
-#if 0
-#define TDB_REF_PAGE(pPage)     (++(pPage)->nRef)
-#define TDB_UNREF_PAGE(pPage)   (--(pPage)->nRef)
-#define TDB_GET_PAGE_REF(pPage) ((pPage)->nRef)
-#else
-#define TDB_REF_PAGE(pPage)     atomic_add_fetch_32(&((pPage)->nRef), 1)
-#define TDB_UNREF_PAGE(pPage)   atomic_sub_fetch_32(&((pPage)->nRef), 1)
-#define TDB_GET_PAGE_REF(pPage) atomic_load_32(&((pPage)->nRef))
-#endif
-
 static int    tdbPCacheOpenImpl(SPCache *pCache);
 static void   tdbPCacheInitLock(SPCache *pCache);
 static void   tdbPCacheClearLock(SPCache *pCache);
@@ -107,12 +95,7 @@ void tdbPCacheRelease(SPCache *pCache, SPage *pPage) {
   ASSERT(nRef >= 0);
 
   if (nRef == 0) {
-    if (1 /*TODO: page still clean*/) {
-      tdbPCacheUnpinPage(pCache, pPage);
-    } else {
-      // TODO
-      ASSERT(0);
-    }
+    tdbPCacheUnpinPage(pCache, pPage);
   }
 }
 
@@ -192,6 +175,8 @@ static void tdbPCacheUnpinPage(SPCache *pCache, SPage *pPage) {
 
   tdbPCacheLock(pCache);
 
+  ASSERT(!pPage->isDirty);
+
   nRef = TDB_GET_PAGE_REF(pPage);
   ASSERT(nRef >= 0);
   if (nRef == 0) {
diff --git a/source/libs/tdb/src/db/tdbPager.c b/source/libs/tdb/src/db/tdbPager.c
index 748633da34..2bc40a6aad 100644
--- a/source/libs/tdb/src/db/tdbPager.c
+++ b/source/libs/tdb/src/db/tdbPager.c
@@ -15,20 +15,6 @@
 
 #include "tdbInt.h"
 
-struct SPager {
-  char    *dbFileName;
-  char    *jFileName;
-  int      pageSize;
-  uint8_t  fid[TDB_FILE_ID_LEN];
-  tdb_fd_t fd;
-  tdb_fd_t jfd;
-  SPCache *pCache;
-  SPgno    dbFileSize;
-  SPgno    dbOrigSize;
-  SPage   *pDirty;
-  u8       inTran;
-};
-
 typedef struct __attribute__((__packed__)) {
   u8    hdrString[16];
   u16   pageSize;
@@ -41,9 +27,8 @@ TDB_STATIC_ASSERT(sizeof(SFileHdr) == 128, "Size of file header is not correct")
 
 #define TDB_PAGE_INITIALIZED(pPage) ((pPage)->pPager != NULL)
 
-static int tdbPagerReadPage(SPager *pPager, SPage *pPage);
 static int tdbPagerAllocPage(SPager *pPager, SPgno *ppgno);
-static int tdbPagerInitPage(SPager *pPager, SPage *pPage, int (*initPage)(SPage *, void *), void *arg);
+static int tdbPagerInitPage(SPager *pPager, SPage *pPage, int (*initPage)(SPage *, void *), void *arg, u8 loadPage);
 static int tdbPagerWritePageToJournal(SPager *pPager, SPage *pPage);
 static int tdbPagerWritePageToDB(SPager *pPager, SPage *pPage);
 
@@ -131,26 +116,36 @@ int tdbPagerOpenDB(SPager *pPager, SPgno *ppgno, bool toCreate) {
 }
 
 int tdbPagerWrite(SPager *pPager, SPage *pPage) {
-  int ret;
+  int     ret;
+  SPage **ppPage;
 
+  ASSERT(pPager->inTran);
+#if 0
   if (pPager->inTran == 0) {
     ret = tdbPagerBegin(pPager);
     if (ret < 0) {
       return -1;
     }
   }
+#endif
 
   if (pPage->isDirty) return 0;
 
+  // ref page one more time so the page will not be release
+  TDB_REF_PAGE(pPage);
+
   // Set page as dirty
   pPage->isDirty = 1;
 
-  // Add page to dirty list
-  // TODO: sort the list according to the page number
-  pPage->pDirtyNext = pPager->pDirty;
-  pPager->pDirty = pPage;
+  // Add page to dirty list(TODO: NOT use O(n^2) algorithm)
+  for (ppPage = &pPager->pDirty; (*ppPage) && TDB_PAGE_PGNO(*ppPage) < TDB_PAGE_PGNO(pPage);
+       ppPage = &((*ppPage)->pDirtyNext)) {
+  }
+  ASSERT(*ppPage == NULL || TDB_PAGE_PGNO(*ppPage) > TDB_PAGE_PGNO(pPage));
+  pPage->pDirtyNext = *ppPage;
+  *ppPage = pPage;
 
-  // Write page to journal
+  // Write page to journal if neccessary
   if (TDB_PAGE_PGNO(pPage) <= pPager->dbOrigSize) {
     ret = tdbPagerWritePageToJournal(pPager, pPage);
     if (ret < 0) {
@@ -184,54 +179,46 @@ int tdbPagerCommit(SPager *pPager) {
   SPage *pPage;
   int    ret;
 
-  // Begin commit
-  {
-    // TODO: Sync the journal file (Here or when write ?)
+  // sync the journal file
+  ret = tdbOsFSync(pPager->jfd);
+  if (ret < 0) {
+    // TODO
+    ASSERT(0);
+    return 0;
   }
 
-  for (;;) {
-    pPage = pPager->pDirty;
-
-    if (pPage == NULL) break;
-
+  // loop to write the dirty pages to file
+  for (pPage = pPager->pDirty; pPage; pPage = pPage->pDirtyNext) {
+    // TODO: update the page footer
     ret = tdbPagerWritePageToDB(pPager, pPage);
     if (ret < 0) {
       ASSERT(0);
       return -1;
     }
+  }
 
+  // release the page
+  for (pPage = pPager->pDirty; pPage; pPage = pPager->pDirty) {
     pPager->pDirty = pPage->pDirtyNext;
     pPage->pDirtyNext = NULL;
 
-    // TODO: release the page
+    pPage->isDirty = 0;
+
+    tdbPCacheRelease(pPager->pCache, pPage);
   }
 
+  // sync the db file
   tdbOsFSync(pPager->fd);
 
+  // remote the journal file
   tdbOsClose(pPager->jfd);
   tdbOsRemove(pPager->jFileName);
-  // pPager->jfd = -1;
+  pPager->dbOrigSize = pPager->dbFileSize;
+  pPager->inTran = 0;
 
   return 0;
 }
 
-static int tdbPagerReadPage(SPager *pPager, SPage *pPage) {
-  i64 offset;
-  int ret;
-
-  ASSERT(memcmp(pPager->fid, pPage->pgid.fileid, TDB_FILE_ID_LEN) == 0);
-
-  offset = (pPage->pgid.pgno - 1) * (i64)(pPager->pageSize);
-  ret = tdbOsPRead(pPager->fd, pPage->pData, pPager->pageSize, offset);
-  if (ret < 0) {
-    // TODO: handle error
-    return -1;
-  }
-  return 0;
-}
-
-int tdbPagerGetPageSize(SPager *pPager) { return pPager->pageSize; }
-
 int tdbPagerFetchPage(SPager *pPager, SPgno pgno, SPage **ppPage, int (*initPage)(SPage *, void *), void *arg) {
   SPage *pPage;
   SPgid  pgid;
@@ -247,7 +234,7 @@ int tdbPagerFetchPage(SPager *pPager, SPgno pgno, SPage **ppPage, int (*initPage
 
   // Initialize the page if need
   if (!TDB_PAGE_INITIALIZED(pPage)) {
-    ret = tdbPagerInitPage(pPager, pPage, initPage, arg);
+    ret = tdbPagerInitPage(pPager, pPage, initPage, arg, 1);
     if (ret < 0) {
       return -1;
     }
@@ -284,7 +271,7 @@ int tdbPagerNewPage(SPager *pPager, SPgno *ppgno, SPage **ppPage, int (*initPage
   ASSERT(!TDB_PAGE_INITIALIZED(pPage));
 
   // Initialize the page if need
-  ret = tdbPagerInitPage(pPager, pPage, initPage, arg);
+  ret = tdbPagerInitPage(pPager, pPage, initPage, arg, 0);
   if (ret < 0) {
     return -1;
   }
@@ -332,10 +319,11 @@ static int tdbPagerAllocPage(SPager *pPager, SPgno *ppgno) {
   return 0;
 }
 
-static int tdbPagerInitPage(SPager *pPager, SPage *pPage, int (*initPage)(SPage *, void *), void *arg) {
+static int tdbPagerInitPage(SPager *pPager, SPage *pPage, int (*initPage)(SPage *, void *), void *arg, u8 loadPage) {
   int ret;
   int lcode;
   int nLoops;
+  i64 nRead;
 
   lcode = TDB_TRY_LOCK_PAGE(pPage);
   if (lcode == P_LOCK_SUCC) {
@@ -344,6 +332,19 @@ static int tdbPagerInitPage(SPager *pPager, SPage *pPage, int (*initPage)(SPage
       return 0;
     }
 
+    if (loadPage) {
+      nRead = tdbOsPRead(pPager->fd, pPage->pData, pPage->pageSize, ((i64)pPage->pageSize) * TDB_PAGE_PGNO(pPage));
+      if (nRead < 0) {
+        // TODO
+        ASSERT(0);
+        return -1;
+      } else if (nRead < pPage->pageSize) {
+        // TODO
+        ASSERT(0);
+        return -1;
+      }
+    }
+
     ret = (*initPage)(pPage, arg);
     if (ret < 0) {
       TDB_UNLOCK_PAGE(pPage);
diff --git a/source/libs/tdb/src/db/tdbTxn.c b/source/libs/tdb/src/db/tdbTxn.c
index fd4d5de60e..03bcbb44a7 100644
--- a/source/libs/tdb/src/db/tdbTxn.c
+++ b/source/libs/tdb/src/db/tdbTxn.c
@@ -15,17 +15,29 @@
 
 #include "tdbInt.h"
 
-int tdbTxnBegin(TENV *pEnv) {
-  // TODO
-  return 0;
-}
+// int tdbTxnBegin(TENV *pEnv) {
+//   // TODO
+//   return 0;
+// }
 
-int tdbTxnCommit(TENV *pEnv) {
-  // TODO
-  return 0;
-}
+// int tdbTxnCommit(TENV *pEnv) {
+//   SPager *pPager = NULL;
+//   int     ret;
 
-int tdbTxnRollback(TENV *pEnv) {
-  // TODO
-  return 0;
-}
\ No newline at end of file
+//   for (;;) {
+//     break;
+//     ret = tdbPagerCommit(pPager);
+//     if (ret < 0) {
+//       ASSERT(0);
+//       return -1;
+//     }
+//   }
+
+//   // TODO
+//   return 0;
+// }
+
+// int tdbTxnRollback(TENV *pEnv) {
+//   // TODO
+//   return 0;
+// }
\ No newline at end of file
diff --git a/source/libs/tdb/src/inc/tdbBtree.h b/source/libs/tdb/src/inc/tdbBtree.h
index 2797b5ea5e..2eba5f4f1a 100644
--- a/source/libs/tdb/src/inc/tdbBtree.h
+++ b/source/libs/tdb/src/inc/tdbBtree.h
@@ -40,7 +40,7 @@ struct SBTC {
 // SBTree
 int tdbBtreeOpen(int keyLen, int valLen, SPager *pFile, FKeyComparator kcmpr, SBTree **ppBt);
 int tdbBtreeClose(SBTree *pBt);
-int tdbBtCursorInsert(SBTC *pCur, const void *pKey, int kLen, const void *pVal, int vLen);
+int tdbBtreeInsert(SBTree *pBt, const void *pKey, int kLen, const void *pVal, int vLen);
 int tdbBtreeGet(SBTree *pBt, const void *pKey, int kLen, void **ppVal, int *vLen);
 int tdbBtreePGet(SBTree *pBt, const void *pKey, int kLen, void **ppKey, int *pkLen, void **ppVal, int *vLen);
 
diff --git a/source/libs/tdb/src/inc/tdbEnv.h b/source/libs/tdb/src/inc/tdbEnv.h
index a651c3a12e..e10c5d54e0 100644
--- a/source/libs/tdb/src/inc/tdbEnv.h
+++ b/source/libs/tdb/src/inc/tdbEnv.h
@@ -25,11 +25,20 @@ typedef struct STEnv {
   char    *jfname;
   int      jfd;
   SPCache *pCache;
+  SPager  *pgrList;
+  int      nPager;
+  int      nPgrHash;
+  SPager **pgrHash;
 } TENV;
 
 int tdbEnvOpen(const char *rootDir, int pageSize, int cacheSize, TENV **ppEnv);
 int tdbEnvClose(TENV *pEnv);
+int tdbBegin(TENV *pEnv);
+int tdbCommit(TENV *pEnv);
+int tdbRollback(TENV *pEnv);
 
+void    tdbEnvAddPager(TENV *pEnv, SPager *pPager);
+void    tdbEnvRemovePager(TENV *pEnv, SPager *pPager);
 SPager *tdbEnvGetPager(TENV *pEnv, const char *fname);
 
 #ifdef __cplusplus
diff --git a/source/libs/tdb/src/inc/tdbInt.h b/source/libs/tdb/src/inc/tdbInt.h
index 361a460cef..57e01f904c 100644
--- a/source/libs/tdb/src/inc/tdbInt.h
+++ b/source/libs/tdb/src/inc/tdbInt.h
@@ -16,8 +16,6 @@
 #ifndef _TD_TDB_INTERNAL_H_
 #define _TD_TDB_INTERNAL_H_
 
-#include "os.h"
-
 #include "tdb.h"
 
 #ifdef __cplusplus
@@ -91,23 +89,6 @@ static FORCE_INLINE int tdbCmprPgId(const void *p1, const void *p2) {
 // dbname
 #define TDB_MAX_DBNAME_LEN 24
 
-// tdb_log
-#define tdbError(var)
-
-#define TERR_A(val, op, flag)  \
-  do {                         \
-    if (((val) = (op)) != 0) { \
-      goto flag;               \
-    }                          \
-  } while (0)
-
-#define TERR_B(val, op, flag)     \
-  do {                            \
-    if (((val) = (op)) == NULL) { \
-      goto flag;                  \
-    }                             \
-  } while (0)
-
 #define TDB_VARIANT_LEN ((int)-1)
 
 typedef int (*FKeyComparator)(const void *pKey1, int kLen1, const void *pKey2, int kLen2);
diff --git a/source/libs/tdb/src/inc/tdbOs.h b/source/libs/tdb/src/inc/tdbOs.h
index 196bbdafc7..ae389708f4 100644
--- a/source/libs/tdb/src/inc/tdbOs.h
+++ b/source/libs/tdb/src/inc/tdbOs.h
@@ -24,6 +24,8 @@ extern "C" {
 #define TDB_FOR_TDENGINE
 
 #ifdef TDB_FOR_TDENGINE
+#include "os.h"
+#include "thash.h"
 
 // For memory -----------------
 #define tdbOsMalloc  taosMemoryMalloc
@@ -95,7 +97,11 @@ typedef int tdb_fd_t;
 
 #define tdbOsOpen(PATH, OPTION, MODE) open((PATH), (OPTION), (MODE))
 
-#define tdbOsClose close
+#define tdbOsClose(FD) \
+  do {                 \
+    close(FD);         \
+    (FD) = -1;         \
+  } while (0)
 
 i64 tdbOsRead(tdb_fd_t fd, void *pData, i64 nBytes);
 i64 tdbOsPRead(tdb_fd_t fd, void *pData, i64 nBytes, i64 offset);
diff --git a/source/libs/tdb/src/inc/tdbPCache.h b/source/libs/tdb/src/inc/tdbPCache.h
index c7fa155615..f71d34ab53 100644
--- a/source/libs/tdb/src/inc/tdbPCache.h
+++ b/source/libs/tdb/src/inc/tdbPCache.h
@@ -33,6 +33,18 @@ extern "C" {
   SPager *pPager;       \
   SPgid   pgid;
 
+// For page ref
+#define TDB_INIT_PAGE_REF(pPage) ((pPage)->nRef = 0)
+#if 0
+#define TDB_REF_PAGE(pPage)     (++(pPage)->nRef)
+#define TDB_UNREF_PAGE(pPage)   (--(pPage)->nRef)
+#define TDB_GET_PAGE_REF(pPage) ((pPage)->nRef)
+#else
+#define TDB_REF_PAGE(pPage)     atomic_add_fetch_32(&((pPage)->nRef), 1)
+#define TDB_UNREF_PAGE(pPage)   atomic_sub_fetch_32(&((pPage)->nRef), 1)
+#define TDB_GET_PAGE_REF(pPage) atomic_load_32(&((pPage)->nRef))
+#endif
+
 int    tdbPCacheOpen(int pageSize, int cacheSize, SPCache **ppCache);
 int    tdbPCacheClose(SPCache *pCache);
 SPage *tdbPCacheFetch(SPCache *pCache, const SPgid *pPgid, bool alcNewPage);
diff --git a/source/libs/tdb/src/inc/tdbPage.h b/source/libs/tdb/src/inc/tdbPage.h
index 563fb53e98..77a1ee5f6e 100644
--- a/source/libs/tdb/src/inc/tdbPage.h
+++ b/source/libs/tdb/src/inc/tdbPage.h
@@ -100,6 +100,7 @@ struct SPage {
 // APIs
 #define TDB_PAGE_TOTAL_CELLS(pPage)        ((pPage)->nOverflow + (pPage)->pPageMethods->getCellNum(pPage))
 #define TDB_PAGE_USABLE_SIZE(pPage)        ((u8 *)(pPage)->pPageFtr - (pPage)->pCellIdx)
+#define TDB_PAGE_FREE_SIZE(pPage)          (*(pPage)->pPageMethods->getFreeBytes)(pPage)
 #define TDB_PAGE_PGNO(pPage)               ((pPage)->pgid.pgno)
 #define TDB_BYTES_CELL_TAKEN(pPage, pCell) ((*(pPage)->xCellSize)(pPage, pCell) + (pPage)->pPageMethods->szOffset)
 #define TDB_PAGE_OFFSET_SIZE(pPage)        ((pPage)->pPageMethods->szOffset)
diff --git a/source/libs/tdb/src/inc/tdbPager.h b/source/libs/tdb/src/inc/tdbPager.h
index f4cc822f27..81b6074431 100644
--- a/source/libs/tdb/src/inc/tdbPager.h
+++ b/source/libs/tdb/src/inc/tdbPager.h
@@ -20,13 +20,28 @@
 extern "C" {
 #endif
 
+struct SPager {
+  char    *dbFileName;
+  char    *jFileName;
+  int      pageSize;
+  uint8_t  fid[TDB_FILE_ID_LEN];
+  tdb_fd_t fd;
+  tdb_fd_t jfd;
+  SPCache *pCache;
+  SPgno    dbFileSize;
+  SPgno    dbOrigSize;
+  SPage   *pDirty;
+  u8       inTran;
+  SPager  *pNext;      // used by TENV
+  SPager  *pHashNext;  // used by TENV
+};
+
 int  tdbPagerOpen(SPCache *pCache, const char *fileName, SPager **ppPager);
 int  tdbPagerClose(SPager *pPager);
 int  tdbPagerOpenDB(SPager *pPager, SPgno *ppgno, bool toCreate);
 int  tdbPagerWrite(SPager *pPager, SPage *pPage);
 int  tdbPagerBegin(SPager *pPager);
 int  tdbPagerCommit(SPager *pPager);
-int  tdbPagerGetPageSize(SPager *pPager);
 int  tdbPagerFetchPage(SPager *pPager, SPgno pgno, SPage **ppPage, int (*initPage)(SPage *, void *), void *arg);
 int  tdbPagerNewPage(SPager *pPager, SPgno *ppgno, SPage **ppPage, int (*initPage)(SPage *, void *), void *arg);
 void tdbPagerReturnPage(SPager *pPager, SPage *pPage);
diff --git a/source/libs/tdb/src/inc/tdbTxn.h b/source/libs/tdb/src/inc/tdbTxn.h
index cc11369785..0be2dad3c2 100644
--- a/source/libs/tdb/src/inc/tdbTxn.h
+++ b/source/libs/tdb/src/inc/tdbTxn.h
@@ -28,10 +28,6 @@ struct STxn {
   void *xArg;
 };
 
-int tdbTxnBegin(TENV *pEnv);
-int tdbTxnCommit(TENV *pEnv);
-int tdbTxnRollback(TENV *pEnv);
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/libs/tdb/src/inc/tdbUtil.h b/source/libs/tdb/src/inc/tdbUtil.h
index c06d9d18c9..6abddb5b22 100644
--- a/source/libs/tdb/src/inc/tdbUtil.h
+++ b/source/libs/tdb/src/inc/tdbUtil.h
@@ -101,6 +101,8 @@ static inline int tdbGetVarInt(const u8 *p, int *v) {
   return n;
 }
 
+static inline u32 tdbCstringHash(const char *s) { return MurmurHash3_32(s, strlen(s)); }
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/libs/tdb/test/tdbTest.cpp b/source/libs/tdb/test/tdbTest.cpp
index f41e2bcbee..9e1277a53d 100644
--- a/source/libs/tdb/test/tdbTest.cpp
+++ b/source/libs/tdb/test/tdbTest.cpp
@@ -118,10 +118,10 @@ TEST(tdb_test, simple_test) {
   TENV          *pEnv;
   TDB           *pDb;
   FKeyComparator compFunc;
-  int            nData = 1000000;
+  int            nData = 50000000;
 
   // Open Env
-  ret = tdbEnvOpen("tdb", 4096, 256000, &pEnv);
+  ret = tdbEnvOpen("tdb", 4096, 64, &pEnv);
   GTEST_ASSERT_EQ(ret, 0);
 
   // Create a database
@@ -134,36 +134,23 @@ TEST(tdb_test, simple_test) {
     char val[64];
 
     {  // Insert some data
-      int       i = 1;
-      SPoolMem *pPool;
-      int       memPoolCapacity = 16 * 1024;
+      for (int i = 1; i <= nData;) {
+        tdbBegin(pEnv);
 
-      pPool = openPool();
-
-      tdbTxnBegin(pEnv);
-
-      for (;;) {
-        if (i > nData) break;
-
-        sprintf(key, "key%d", i);
-        sprintf(val, "value%d", i);
-        ret = tdbDbInsert(pDb, key, strlen(key), val, strlen(val));
-        GTEST_ASSERT_EQ(ret, 0);
-
-        if (pPool->size >= memPoolCapacity) {
-          tdbTxnCommit(pEnv);
-
-          clearPool(pPool);
-
-          tdbTxnBegin(pEnv);
+        for (int k = 0; k < 2000; k++) {
+          sprintf(key, "key%d", i);
+          sprintf(val, "value%d", i);
+          ret = tdbDbInsert(pDb, key, strlen(key), val, strlen(val));
+          GTEST_ASSERT_EQ(ret, 0);
+          i++;
         }
 
-        i++;
+        tdbCommit(pEnv);
       }
-
-      closePool(pPool);
     }
 
+    tdbCommit(pEnv);
+
     {  // Query the data
       void *pVal = NULL;
       int   vLen;
@@ -173,6 +160,7 @@ TEST(tdb_test, simple_test) {
         sprintf(val, "value%d", i);
 
         ret = tdbDbGet(pDb, key, strlen(key), &pVal, &vLen);
+        ASSERT(ret == 0);
         GTEST_ASSERT_EQ(ret, 0);
 
         GTEST_ASSERT_EQ(vLen, strlen(val));