diff --git a/source/libs/index/inc/index_fst.h b/source/libs/index/inc/index_fst.h
index 37feb79ac8..8f76c2d5cf 100644
--- a/source/libs/index/inc/index_fst.h
+++ b/source/libs/index/inc/index_fst.h
@@ -251,8 +251,14 @@ void         fstDestroy(Fst *fst);
 
 bool         fstGet(Fst *fst, FstSlice *b, Output *out);
 FstNode*     fstGetNode(Fst *fst, CompiledAddr); 
+FstNode*     fstGetRoot(Fst *fst);
 FstType      fstGetType(Fst *fst); 
 CompiledAddr fstGetRootAddr(Fst *fst);
+
 Output fstEmptyFinalOutput(Fst *fst, bool *null);
 bool fstVerify(Fst *fst);
+
+
+//refactor this function 
+bool fstBuilderNodeCompileTo(FstBuilderNode *b, FstCountingWriter *wrt, CompiledAddr lastAddr, CompiledAddr startAddr); 
 #endif
diff --git a/source/libs/index/inc/index_fst_node.h b/source/libs/index/inc/index_fst_node.h
index ddd7e1f450..0645aa1158 100644
--- a/source/libs/index/inc/index_fst_node.h
+++ b/source/libs/index/inc/index_fst_node.h
@@ -41,7 +41,7 @@ FstBuilderNode *fstBuilderNodeClone(FstBuilderNode *src);
 
 void fstBuilderNodeCloneFrom(FstBuilderNode *dst, FstBuilderNode *src);
 
-bool fstBuilderNodeCompileTo(FstBuilderNode *b, FstCountingWriter *wrt, CompiledAddr lastAddr, CompiledAddr startAddr); 
+//bool fstBuilderNodeCompileTo(FstBuilderNode *b, FstCountingWriter *wrt, CompiledAddr lastAddr, CompiledAddr startAddr); 
 
 void fstBuilderNodeDestroy(FstBuilderNode *node);
 
diff --git a/source/libs/index/src/index_fst.c b/source/libs/index/src/index_fst.c
index 6c1ea8cfeb..94be05d0c1 100644
--- a/source/libs/index/src/index_fst.c
+++ b/source/libs/index/src/index_fst.c
@@ -733,6 +733,11 @@ bool fstNodeCompile(FstNode *node, void *w, CompiledAddr lastAddr, CompiledAddr
   return true; 
 } 
 
+bool fstBuilderNodeCompileTo(FstBuilderNode *b, FstCountingWriter *wrt, CompiledAddr lastAddr, CompiledAddr startAddr) {
+  return fstNodeCompile(NULL, wrt, lastAddr, startAddr, b);
+}
+
+
 
 FstBuilder *fstBuilderCreate(void *w, FstType ty) {
   FstBuilder *b = malloc(sizeof(FstBuilder));  
@@ -985,15 +990,39 @@ void fstDestroy(Fst *fst) {
 }
 
 bool fstGet(Fst *fst, FstSlice *b, Output *out) {
-   
+  FstNode *root = fstGetRoot(fst);    
+  Output tOut = 0; 
+  for (uint32_t i = 0; i < b->dLen; i++) {
+    uint8_t inp = b->data[i];
+    Output  res = 0;
+    bool null = fstNodeFindInput(root, inp, &res);    
+    if (null) { return false; }    
+
+    FstTransition trn; 
+    fstNodeGetTransitionAt(root, res, &trn);
+    tOut += trn.out; 
+    root = fstGetNode(fst, trn.addr);
+  }
+  if (!FST_NODE_IS_FINAL(root)) {
+    return false;
+  } else {
+    tOut = tOut + FST_NODE_FINAL_OUTPUT(root); 
+  }
+  *out = tOut;
+  
   return false; 
 }
 
+FstNode *fstGetRoot(Fst *fst) {
+  CompiledAddr root = fstGetRootAddr(fst); 
+  return fstGetNode(fst, root);
+}
 FstNode* fstGetNode(Fst *fst, CompiledAddr addr) {
   if (fst->root != NULL) {
     return fst->root;
   }
   fst->root = fstNodeCreate(fst->meta->version, addr, fst->data); 
+  
   return fst->root;
   
 }
@@ -1016,15 +1045,14 @@ Output fstEmptyFinalOutput(Fst *fst, bool *null) {
   return res;
 }
 
-
 bool fstVerify(Fst *fst) {
   uint32_t checkSum = fst->meta->checkSum;
   FstSlice *data    = fst->data;          
   TSCKSUM initSum  = 0;  
-  if (taosCheckChecksumWhole(data->data, data->dLen)) {
+  if (!taosCheckChecksumWhole(data->data, data->dLen)) {
     return false;
   }
-  
+  return true;
 }
 
 
diff --git a/source/libs/index/src/index_fst_node.c b/source/libs/index/src/index_fst_node.c
index 5452f9cb89..b33b8e4428 100644
--- a/source/libs/index/src/index_fst_node.c
+++ b/source/libs/index/src/index_fst_node.c
@@ -59,26 +59,27 @@ void fstBuilderNodeCloneFrom(FstBuilderNode *dst, FstBuilderNode *src) {
   src->trans = NULL;
 }
 
-bool fstBuilderNodeCompileTo(FstBuilderNode *b, FstCountingWriter *wrt, CompiledAddr lastAddr, CompiledAddr startAddr) {
-  size_t sz = taosArrayGetSize(b->trans);  
-  assert(sz < 256);
-  if (FST_BUILDER_NODE_IS_FINAL(b) 
-      && FST_BUILDER_NODE_TRANS_ISEMPTY(b) 
-      && FST_BUILDER_NODE_FINALOUTPUT_ISZERO(b)) {
-    return true; 
-  } else if (sz != 1 || b->isFinal) {
-    // AnyTrans->Compile(w, addr, node);
-  } else {
-    FstTransition *tran = taosArrayGet(b->trans, 0);   
-    if (tran->addr == lastAddr && tran->out == 0) {
-       //OneTransNext::compile(w, lastAddr, tran->inp);
-       return true;
-    } else {
-      //OneTrans::Compile(w, lastAddr, *tran);
-       return true;
-    } 
-  } 
-  return true; 
-} 
+//bool fstBuilderNodeCompileTo(FstBuilderNode *b, FstCountingWriter *wrt, CompiledAddr lastAddr, CompiledAddr startAddr) {
+  
+  //size_t sz = taosArrayGetSize(b->trans);  
+  //assert(sz < 256);
+  //if (FST_BUILDER_NODE_IS_FINAL(b) 
+  //    && FST_BUILDER_NODE_TRANS_ISEMPTY(b) 
+  //    && FST_BUILDER_NODE_FINALOUTPUT_ISZERO(b)) {
+  //  return true; 
+  //} else if (sz != 1 || b->isFinal) {
+  //  // AnyTrans->Compile(w, addr, node);
+  //} else {
+  //  FstTransition *tran = taosArrayGet(b->trans, 0);   
+  //  if (tran->addr == lastAddr && tran->out == 0) {
+  //     //OneTransNext::compile(w, lastAddr, tran->inp);
+  //     return true;
+  //  } else {
+  //    //OneTrans::Compile(w, lastAddr, *tran);
+  //     return true;
+  //  } 
+  //} 
+  //return true; 
+//}