diff --git a/src/tsdb/src/tsdbReadUtil.c b/src/tsdb/src/tsdbReadUtil.c
index 54966daf4db458e9c3e5979b1b117a4eb02469b1..d78b4e3a0c22713725b6231f5aea00bfe1768b16 100644
--- a/src/tsdb/src/tsdbReadUtil.c
+++ b/src/tsdb/src/tsdbReadUtil.c
@@ -16,8 +16,10 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 
-#include "tsdbMain.h"
 #include "tchecksum.h"
+#include "tdataformat.h"
+#include "tscompression.h"
+#include "tsdbMain.h"
 
 typedef struct {
   STsdbRepo * pRepo;
@@ -26,8 +28,8 @@ typedef struct {
   TSKEY       maxKey;
   SBlockIdx * pBlockIdx;
   int         nBlockIdx;
-  uint64_t    uid;
-  int32_t     tid;
+  SBlockIdx * pCurBlockIdx;
+  STable *    pTable;
   SBlockInfo *pBlockInfo;
   SDataCols * pDataCols[2];
   void *      pBuf;
@@ -35,6 +37,7 @@ typedef struct {
 } SReadHandle;
 
 #define TSDB_READ_FILE(pReadH, type) (&((pReadH)->fGroup.files[(type)]))
+#define TSDB_BLOCK_DATA_LEN(nCols) (sizeof(SBlockData) + sizeof(SBlockCol) * (nCols) + sizeof(TSCKSUM))
 
 int tsdbInitReadHandle(SReadHandle *pReadH, STsdbRepo *pRepo) {
   pReadH->pRepo = pRepo;
@@ -125,6 +128,182 @@ int tsdbLoadBlockIdx(SReadHandle *pReadH) {
   return 0;
 }
 
+int tsdbSetReadTable(SReadHandle *pReadH, STable *pTable) {
+  pReadH->pTable = pTable;
+  // TODO
+  // pReadH->pCurBlockIdx = NULL;
+  return 0;
+}
+
+int tsdbLoadBlockInfo(SReadHandle *pReadH) {
+  if (pReadH->pCurBlockIdx == NULL) return 0;
+
+  SFile *    pFile = TSDB_READ_FILE(pReadH, TSDB_FILE_TYPE_HEAD);
+  SBlockIdx *pBlockIdx = pReadH->pCurBlockIdx;
+  STsdbRepo *pRepo = pReadH->pRepo;
+
+  ASSERT(pFile->fd > 0);
+
+  if (tsdbAllocBuf(&((void *)pReadH->pBlockInfo), pBlockIdx->len) < 0) {
+    terrno = TSDB_CODE_TDB_OUT_OF_MEMORY;
+    return -1;
+  }
+
+  if (lseek(pFile->fd, pBlockIdx->offset, SEEK_SET) < 0) {
+    tsdbError("vgId:%d failed to lseek file %s since %s", REPO_ID(pRepo), pFile->fname, strerror(errno));
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    return -1;
+  }
+
+  ssize_t ret = taosTRead(pFile->fd, (void *)pReadH->pBlockInfo, pBlockIdx->len);
+  if (ret < 0) {
+    tsdbError("vgId:%d failed to read block info part of table %s from file %s since %s", REPO_ID(pRepo),
+              TABLE_CHAR_NAME(pReadH->pTable), pFile->fname, strerror(errno));
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    return -1;
+  }
+
+  if (ret < pBlockIdx->len || tsdbVerifyBlockInfo(pReadH->pBlockInfo, pBlockIdx) < 0) {
+    tsdbError("vgId:%d table %s block info part is corrupted from file %s since %s", REPO_ID(pRepo),
+              TABLE_CHAR_NAME(pReadH->pTable), pFile->fname, strerror(errno));
+    terrno = TSDB_CODE_TDB_FILE_CORRUPTED;
+    return -1;
+  }
+
+  return 0;
+}
+
+int tsdbLoadBlockData(SReadHandle *pReadH, SBlock *pBlock, SBlockInfo *pBlockInfo) {
+  // TODO
+  SBlock *pSubBlock = pBlock;
+  int     nSubBlocks = pBlock->numOfSubBlocks;
+
+  if (nSubBlocks > 1) {
+    if (pBlockInfo == NULL) pBlockInfo = pReadH->pBlockInfo;
+    pSubBlock = (SBlock *)POINTER_SHIFT((void *)pReadH->pBlockInfo, pBlock->offset);
+  }
+
+  if (tsdbLoadBlockDataImpl(pReadH, pSubBlock, pReadH->pDataCols[0]) < 0) return -1;
+  for (int i = 1; i < nSubBlocks; i++) {
+    pSubBlock++;
+    if (tsdbLoadBlockDataImpl(pReadH, pSubBlock, pReadH->pDataCols[1]) < 0) return -1;
+    if (tdMergeDataCols(pReadH->pDataCols[0], pReadH->pDataCols[1], pReadH->pDataCols[1]->numOfRows) < 0) return -1;
+  }
+
+  ASSERT(pReadH->pDataCols[0]->numOfRows == pBlock->numOfRows);
+  ASSERT(dataColsKeyFirst(pReadH->pDataCols[0]) == pBlock->keyFirst);
+  ASSERT(dataColsKeyLast(pReadH->pDataCols[0]) == pBlock->keyLast);
+
+  return 0;
+}
+
+int tsdbLoadBlockDataCols(SReadHandle *pReadH, SBlock *pBlock, SBlockInfo *pBlockInfo, int16_t *colIds, int numOfCols) {
+  // TODO
+  return 0;
+}
+
+static int tsdbLoadBlockDataImpl(SReadHandle *pReadH, SBlock *pBlock, SDataCols *pDataCols) {
+  ASSERT(pBlock->numOfSubBlocks  <= 1);
+
+  STsdbRepo *pRepo = pReadH->pRepo;
+  SFile *pFile =
+      (pBlock->last) ? TSDB_READ_FILE(pReadH, TSDB_FILE_TYPE_LAST) : TSDB_READ_FILE(pReadH, TSDB_FILE_TYPE_DATA);
+
+  if (tsdbAllocBuf(&(pReadH->pBuf), pBlock->len) < 0) {
+    terrno = TSDB_CODE_TDB_OUT_OF_MEMORY;
+    return -1;
+  }
+
+  if (lseek(pFile->fd, pBlock->offset, SEEK_SET) < 0) {
+    tsdbError("vgId:%d failed to lseek file %s since %s", REPO_ID(pRepo), pFile->fname, strerror(errno));
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    return -1;
+  }
+
+  int ret = taosTRead(pFile->fd, (void *)pReadH->pBuf, pBlock->len);
+  if (ret < 0) {
+    tsdbError("vgId:%d failed to read block data part from file %s since %s", REPO_ID(pRepo), pFile->fname,
+              strerror(errno));
+    terrno = TAOS_SYSTEM_ERROR(errno);
+    return -1;
+  }
+
+  int tsize = TSDB_BLOCK_DATA_LEN(pBlock->numOfCols);
+  if (ret < pBlock->len || !taosCheckChecksumWhole((uint8_t *)pReadH->pBuf, tsize)) {
+    tsdbError("vgId:%d block data part from file %s is corrupted", REPO_ID(pRepo), pFile->fname);
+    terrno = TSDB_CODE_TDB_FILE_CORRUPTED;
+    return -1;
+  }
+
+  SBlockData *pBlockData = (SBlockData *)pReadH->pBuf;
+
+  ASSERT(pBlockData->delimiter == TSDB_FILE_DELIMITER);
+  ASSERT(pBlockData->numOfCols = pBlock->numOfCols);
+
+  tdResetDataCols(pDataCols);
+  pDataCols->numOfRows = pBlock->numOfRows;
+
+  int ccol = 0;
+  int dcol = 0;
+  while (dcol < pDataCols->numOfCols) {
+    SDataCol *pDataCol = &(pDataCols->cols[dcol]);
+    if (dcol != 0 && ccol >= pBlockData->numOfCols) {
+      dataColSetNEleNull(pDataCol, pBlock->numOfRows, pDataCols->maxPoints);
+      dcol++;
+      continue;
+    }
+
+    int16_t tcolId = 0;
+    int32_t toffset = TSDB_KEY_COL_OFFSET;
+    int32_t tlen = pBlock->keyLen;
+
+    if (dcol != 0) {
+      SBlockCol *pBlockCol = &(pBlockData->cols[ccol]);
+      tcolId = pBlockCol->colId;
+      toffset = pBlockCol->offset;
+      tlen = pBlockCol->len;
+    } else {
+      ASSERT(pDataCol->colId == tcolId);
+    }
+
+    if (tcolId == pDataCol->colId) {
+      if (pBlock->algorithm == TWO_STAGE_COMP) {  // extend compression buffer
+        int zsize = pDataCol->bytes * pBlock->numOfRows + COMP_OVERFLOW_BYTES;
+        if (pDataCol->type == TSDB_DATA_TYPE_BINARY || pDataCol->type == TSDB_DATA_TYPE_NCHAR) {
+          zsize += (sizeof(VarDataLenT) * pCompBlock->numOfRows);
+        }
+
+        if (tsdbAllocBuf(&(pReadH->pCBuf), zsize) < 0) {
+          terrno = TSDB_CODE_TDB_OUT_OF_MEMORY;
+          return -1;
+        }
+      }
+      if (tsdbCheckAndDecodeColumnData(pDataCol, POINTER_SHIFT(pBlockData, tsize + toffset), tlen, pBlock->algorithm,
+                                       pBlock->numOfRows, pDataCols->maxPoints, pReadH->pCBuf,
+                                       (int32_t)taosTSizeof(pReadH->pCBuf)) < 0) {
+        tsdbError("vgId:%d file %s is broken at column %d block offset %" PRId64 " column offset %d", REPO_ID(pRepo),
+                  pFile->fname, tcolId, (int64_t)pBlock->offset, toffset);
+        return -1;
+      }
+
+      if (dcol != 0) ccol++;
+      dcol++;
+    } else if (tcolId < pDataCol->colId) {
+      ccol++;
+    } else {
+      dataColSetNEleNull(pDataCol, pBlock->numOfRows, pDataCols->maxPoints);
+      dcol++;
+    }
+  }
+
+  return 0;
+}
+
+static int tsdbLoadBlockDataColsImpl() {
+  // TODO
+  return 0;
+}
+
 static int tsdbDecodeBlockIdxArray(SReadHandle *pReadH) {
   void *pBuf = pReadH->pBuf;
   SFile *pFile = &(pReadH->fGroup.files[TSDB_FILE_TYPE_HEAD]);
@@ -161,4 +340,46 @@ static int tsdbAllocBuf(void **ppBuf, int size) {
 
   *ppBuf = taosTRealloc(pBuf, tsize);
   if (*ppBuf == NULL) return -1;
+}
+
+static int tsdbVerifyBlockInfo(SBlockInfo *pBlockInfo, SBlockIdx *pBlockIdx) {
+  if (!taosCheckChecksumWhole((uint8_t *)pBlockInfo, pBlockIdx->len)) return -1;
+  if (pBlockInfo->delimiter != TSDB_FILE_DELIMITER || pBlockInfo->uid != pBlockIdx->uid ||
+      pBlockInfo->tid != pBlockIdx->tid)
+    return -1;
+  return 0;
+}
+
+static int tsdbCheckAndDecodeColumnData(SDataCol *pDataCol, char *content, int32_t len, int8_t comp, int numOfRows,
+                                        int maxPoints, char *buffer, int bufferSize) {
+  // Verify by checksum
+  if (!taosCheckChecksumWhole((uint8_t *)content, len)) {
+    terrno = TSDB_CODE_TDB_FILE_CORRUPTED;
+    return -1;
+  }
+
+  // Decode the data
+  if (comp) {
+    // // Need to decompress
+    int tlen = (*(tDataTypeDesc[pDataCol->type].decompFunc))(content, len - sizeof(TSCKSUM), numOfRows, pDataCol->pData,
+                                                             pDataCol->spaceSize, comp, buffer, bufferSize);
+    if (tlen <= 0) {
+      tsdbError("Failed to decompress column, file corrupted, len:%d comp:%d numOfRows:%d maxPoints:%d bufferSize:%d",
+                len, comp, numOfRows, maxPoints, bufferSize);
+      terrno = TSDB_CODE_TDB_FILE_CORRUPTED;
+      return -1;
+    }
+    pDataCol->len = tlen;
+    if (pDataCol->type == TSDB_DATA_TYPE_BINARY || pDataCol->type == TSDB_DATA_TYPE_NCHAR) {
+      dataColSetOffset(pDataCol, numOfRows);
+    }
+  } else {
+    // No need to decompress, just memcpy it
+    pDataCol->len = len - sizeof(TSCKSUM);
+    memcpy(pDataCol->pData, content, pDataCol->len);
+    if (pDataCol->type == TSDB_DATA_TYPE_BINARY || pDataCol->type == TSDB_DATA_TYPE_NCHAR) {
+      dataColSetOffset(pDataCol, numOfRows);
+    }
+  }
+  return 0;
 }
\ No newline at end of file