diff --git a/source/libs/index/inc/index_fst.h b/source/libs/index/inc/index_fst.h
new file mode 100644
index 0000000000..de4c957e29
--- /dev/null
+++ b/source/libs/index/inc/index_fst.h
@@ -0,0 +1,166 @@
+/*
+ * 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 _INDEX_FST_H_
+#define _INDEX_FST_H_
+#include "index_fst.h"
+#include "tarray.h"
+
+typedef FstType      uint64_t;
+typedef CompiledAddr uint64_t;
+typedef Output       uint64_t;  
+typedef PackSizes    uint8_t;
+
+
+//A sentinel value used to indicate an empty final state
+const CompileAddr EMPTY_ADDRESS  = 0;
+/// A sentinel value used to indicate an invalid state.
+const CompileAddr NONE_ADDRESS   = 1;
+
+// This version number is written to every finite state transducer created by
+// this crate. When a finite state transducer is read, its version number is
+// checked against this value.
+const uint64_t    version        = 3;
+// The threshold (in number of transitions) at which an index is created for                                   
+// a node's transitions. This speeds up lookup time at the expense of FST size 
+
+const uint64_t TRANS_INDEX_THRESHOLD = 32;
+
+typedef struct FstRange {
+  uint64_t start;
+  uint64_t end;
+} FstRange;
+
+enum State { OneTransNext, OneTrans, AnyTrans, EmptyFinal};
+enum FstBound { Included, Excluded, Unbounded}; 
+
+typedef struct CheckSummer {
+  uint32_t sum;
+};
+
+
+typedef struct FstBuilder {
+  FstCountingWriter  wtr;       // The FST raw data is written directly to `wtr`.  
+  FstUnFinishedNodes unfinished // The stack of unfinished nodes   
+  Registry           registry   // A map of finished nodes.        
+  SArray*            last       // The last word added 
+  CompiledAddr       lastAddr   // The address of the last compiled node  
+  uint64_t           len        // num of keys added
+} FstBuilder;
+
+typedef struct FstCountingWriter {
+  void*    wtr;  // wrap any writer that counts and checksum bytes written 
+  uint64_t count; 
+  CheckSummer summer;  
+};
+
+
+
+
+typedef struct FstTransition {
+  uint8_t      inp;  //The byte input associated with this transition.
+  Output       out;  //The output associated with this transition 
+  CompiledAddr addr; //The address of the node that this transition points to
+} FstTransition;
+
+typedef struct FstTransitions {
+  FstNode    *node; 
+  FstRange   range;   
+} FstTransitions;
+
+typedef struct FstUnFinishedNodes {
+  SArray *stack; // <FstBuilderNodeUnfinished>
+} FstUnFinishedNodes; 
+
+typedef struct FstBuilderNode {
+  bool isFinal; 
+  Output finalOutput;  
+  SArray *trans;  // <FstTransition>
+} FstBuilderNode; 
+
+
+
+typedef struct FstLastTransition {
+  uint8_t inp;
+  Output  out;
+} FstLastTransition;
+
+typedef struct FstBuilderNodeUnfinished {
+  FstBuilderNode    node; 
+  FstLastTransition last; 
+} FstBuilderNodeUnfinished;
+
+typedef struct FstNode {
+  uint8_t*     data;
+  uint64_t     version; 
+  State        state;
+  CompiledAddr start; 
+  CompiledAddr end;  
+  bool         isFinal;
+  uint64_t     nTrans;
+  PackSizes    sizes;
+  Output      finalOutput;
+} FstNode;
+
+typedef struct FstMeta {
+  uint64_t     version;
+  CompiledAddr rootAddr;  
+  FstType      ty;
+  uint64_t     len;
+  uint32_t     checkSum;
+} FstMeta;
+
+typedef struct Fst {
+  FstMeta meta; 
+  void    *data;  //  
+};
+
+// ops 
+
+typedef struct FstIndexedValue {
+  uint64_t index;
+  uint64_t value;
+};
+
+// relate to Regist 
+typedef struct FstRegistry {
+  SArray *table;      // <Registtry cell>
+  uint64_t tableSize; // num of rows
+  uint64_t mruSize;   // num of columns    
+} FstRegistry; 
+
+typedef struct FstRegistryCache {
+  SArray *cells;  //  <RegistryCell>
+} FstRegistryCache;
+
+typedef struct FstRegistryCell {
+  CompiledAddr addr; 
+  FstBuilderNode *node; 
+} FstRegistryCell;
+
+enum FstRegistryEntry {Found, NotFound, Rejected};
+
+FstNode *fstNodeCreate(int64_t version, CompiledAddr addr, uint8_t *data);
+FstTransitions fstNodeTransitionIter(FstNode *node);
+FstTransition  fstNodeGetTransitionAt(FstNode *node, uint64_t i);
+CompiledAddr   fstNodeGetTransitionAddr(FstNode *node, uint64_t i);
+int64_t        fstNodeFindInput(FstNode *node, int8_t b);
+Output         fstNodeGetFinalOutput(FstNode *node);
+void*          fstNodeCompile(FstNode *node, void *w, CompiledAddr lastAddr, CompiledArr addr, FstBuilderNode *builderNode); 
+
+
+
+
+#endif
diff --git a/source/libs/index/src/index_fst.c b/source/libs/index/src/index_fst.c
new file mode 100644
index 0000000000..4c6e20a7d5
--- /dev/null
+++ b/source/libs/index/src/index_fst.c
@@ -0,0 +1,48 @@
+/*
+ * 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 "index_fst.h"
+
+// fst node function 
+FstNode *fstNodeCreate(int64_t version, ComiledAddr addr, uint8_t *data) {
+  FstNode *n = (FstNode *)malloc(sizeof(FstNode)); 
+  if (n == NULL) { return NULL; }
+
+  if (addr == EMPTY_ADDRESS) {
+     n->date = NULL;
+     n->version = version;
+     n->state   = EmptyFinal;  
+     n->start   = EMPTY_ADDRESS;
+     n->end     = EMPTY_ADDRESS;  
+     n->isFinal = true; 
+     n->nTrans  = 0;
+     n->sizes   = 0;  
+     n->finalOutpu = 0;  
+     return n;
+   } 
+   uint8_t v = (data[addr] & 0b1100000) >> 6;
+   if (v == 0b11) {
+      
+   } else if (v == 0b10) {
+    
+   } else {
+
+   } 
+   
+  
+}
+
+
+
diff --git a/source/libs/index/src/index_fst_common.c b/source/libs/index/src/index_fst_common.c
new file mode 100644
index 0000000000..39e5f89b35
--- /dev/null
+++ b/source/libs/index/src/index_fst_common.c
@@ -0,0 +1,304 @@
+/*
+ * 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/>.
+ */
+const uint8_t COMMON_INPUTS[] = {
+    84,  // '\x00'
+    85,  // '\x01'
+    86,  // '\x02'
+    87,  // '\x03'
+    88,  // '\x04'
+    89,  // '\x05'
+    90,  // '\x06'
+    91,  // '\x07'
+    92,  // '\x08'
+    93,  // '\t'
+    94,  // '\n'
+    95,  // '\x0b'
+    96,  // '\x0c'
+    97,  // '\r'
+    98,  // '\x0e'
+    99,  // '\x0f'
+    100, // '\x10'
+    101, // '\x11'
+    102, // '\x12'
+    103, // '\x13'
+    104, // '\x14'
+    105, // '\x15'
+    106, // '\x16'
+    107, // '\x17'
+    108, // '\x18'
+    109, // '\x19'
+    110, // '\x1a'
+    111, // '\x1b'
+    112, // '\x1c'
+    113, // '\x1d'
+    114, // '\x1e'
+    115, // '\x1f'
+    116, // ' '
+    80,  // '!'
+    117, // '"'
+    118, // '#'
+    79,  // '$'
+    39,  // '%'
+    30,  // '&'
+    81,  // "'"
+    75,  // '('
+    74,  // ')'
+    82,  // '*'
+    57,  // '+'
+    66,  // ','
+    16,  // '-'
+    12,  // '.'
+    2,   // '/'
+    19,  // '0'
+    20,  // '1'
+    21,  // '2'
+    27,  // '3'
+    32,  // '4'
+    29,  // '5'
+    35,  // '6'
+    36,  // '7'
+    37,  // '8'
+    34,  // '9'
+    24,  // ':'
+    73,  // ';'
+    119, // '<'
+    23,  // '='
+    120, // '>'
+    40,  // '?'
+    83,  // '@'
+    44,  // 'A'
+    48,  // 'B'
+    42,  // 'C'
+    43,  // 'D'
+    49,  // 'E'
+    46,  // 'F'
+    62,  // 'G'
+    61,  // 'H'
+    47,  // 'I'
+    69,  // 'J'
+    68,  // 'K'
+    58,  // 'L'
+    56,  // 'M'
+    55,  // 'N'
+    59,  // 'O'
+    51,  // 'P'
+    72,  // 'Q'
+    54,  // 'R'
+    45,  // 'S'
+    52,  // 'T'
+    64,  // 'U'
+    65,  // 'V'
+    63,  // 'W'
+    71,  // 'X'
+    67,  // 'Y'
+    70,  // 'Z'
+    77,  // '['
+    121, // '\\'
+    78,  // ']'
+    122, // '^'
+    31,  // '_'
+    123, // '`'
+    4,   // 'a'
+    25,  // 'b'
+    9,   // 'c'
+    17,  // 'd'
+    1,   // 'e'
+    26,  // 'f'
+    22,  // 'g'
+    13,  // 'h'
+    7,   // 'i'
+    50,  // 'j'
+    38,  // 'k'
+    14,  // 'l'
+    15,  // 'm'
+    10,  // 'n'
+    3,   // 'o'
+    8,   // 'p'
+    60,  // 'q'
+    6,   // 'r'
+    5,   // 's'
+    0,   // 't'
+    18,  // 'u'
+    33,  // 'v'
+    11,  // 'w'
+    41,  // 'x'
+    28,  // 'y'
+    53,  // 'z'
+    124, // '{'
+    125, // '|'
+    126, // '}'
+    76,  // '~'
+    127, // '\x7f'
+    128, // '\x80'
+    129, // '\x81'
+    130, // '\x82'
+    131, // '\x83'
+    132, // '\x84'
+    133, // '\x85'
+    134, // '\x86'
+    135, // '\x87'
+    136, // '\x88'
+    137, // '\x89'
+    138, // '\x8a'
+    139, // '\x8b'
+    140, // '\x8c'
+    141, // '\x8d'
+    142, // '\x8e'
+    143, // '\x8f'
+    144, // '\x90'
+    145, // '\x91'
+    146, // '\x92'
+    147, // '\x93'
+    148, // '\x94'
+    149, // '\x95'
+    150, // '\x96'
+    151, // '\x97'
+    152, // '\x98'
+    153, // '\x99'
+    154, // '\x9a'
+    155, // '\x9b'
+    156, // '\x9c'
+    157, // '\x9d'
+    158, // '\x9e'
+    159, // '\x9f'
+    160, // '\xa0'
+    161, // '¡'
+    162, // '¢'
+    163, // '£'
+    164, // '¤'
+    165, // '¥'
+    166, // '¦'
+    167, // '§'
+    168, // '¨'
+    169, // '©'
+    170, // 'ª'
+    171, // '«'
+    172, // '¬'
+    173, // '\xad'
+    174, // '®'
+    175, // '¯'
+    176, // '°'
+    177, // '±'
+    178, // '²'
+    179, // '³'
+    180, // '´'
+    181, // 'µ'
+    182, // '¶'
+    183, // '·'
+    184, // '¸'
+    185, // '¹'
+    186, // 'º'
+    187, // '»'
+    188, // '¼'
+    189, // '½'
+    190, // '¾'
+    191, // '¿'
+    192, // 'À'
+    193, // 'Á'
+    194, // 'Â'
+    195, // 'Ã'
+    196, // 'Ä'
+    197, // 'Å'
+    198, // 'Æ'
+    199, // 'Ç'
+    200, // 'È'
+    201, // 'É'
+    202, // 'Ê'
+    203, // 'Ë'
+    204, // 'Ì'
+    205, // 'Í'
+    206, // 'Î'
+    207, // 'Ï'
+    208, // 'Ð'
+    209, // 'Ñ'
+    210, // 'Ò'
+    211, // 'Ó'
+    212, // 'Ô'
+    213, // 'Õ'
+    214, // 'Ö'
+    215, // '×'
+    216, // 'Ø'
+    217, // 'Ù'
+    218, // 'Ú'
+    219, // 'Û'
+    220, // 'Ü'
+    221, // 'Ý'
+    222, // 'Þ'
+    223, // 'ß'
+    224, // 'à'
+    225, // 'á'
+    226, // 'â'
+    227, // 'ã'
+    228, // 'ä'
+    229, // 'å'
+    230, // 'æ'
+    231, // 'ç'
+    232, // 'è'
+    233, // 'é'
+    234, // 'ê'
+    235, // 'ë'
+    236, // 'ì'
+    237, // 'í'
+    238, // 'î'
+    239, // 'ï'
+    240, // 'ð'
+    241, // 'ñ'
+    242, // 'ò'
+    243, // 'ó'
+    244, // 'ô'
+    245, // 'õ'
+    246, // 'ö'
+    247, // '÷'
+    248, // 'ø'
+    249, // 'ù'
+    250, // 'ú'
+    251, // 'û'
+    252, // 'ü'
+    253, // 'ý'
+    254, // 'þ'
+    255, // 'ÿ'
+};
+
+char const COMMON_INPUTS_INV[] = [
+    't', 'e', '/', 'o', 'a', 's', 'r', 'i', 'p', 'c', 'n', 'w',
+    '.', 'h', 'l', 'm', '-', 'd', 'u', '0', '1', '2', 'g', '=',
+    ':', 'b', 'f', '3', 'y', '5', '&', '_', '4', 'v', '9', '6',
+    '7', '8', 'k', '%', '?', 'x', 'C', 'D', 'A', 'S', 'F', 'I',
+    'B', 'E', 'j', 'P', 'T', 'z', 'R', 'N', 'M', '+', 'L', 'O',
+    'q', 'H', 'G', 'W', 'U', 'V', ',', 'Y', 'K', 'J', 'Z', 'X',
+    'Q', ';', ')', '(', '~', '[', ']', '$', '!', '\'', '*', '@',
+    '\x00', '\x01', '\x02', '\x03', '\x04', '\x05', '\x06', '\x07',
+    '\x08', '\t', '\n', '\x0b', '\x0c', '\r', '\x0e', '\x0f', '\x10',
+    '\x11', '\x12', '\x13', '\x14', '\x15', '\x16', '\x17', '\x18',
+    '\x19', '\x1a', '\x1b', '\x1c', '\x1d', '\x1e', '\x1f', ' ', '"',
+    '#', '<', '>', '\\', '^', '`', '{', '|', '}','\x7f','\x80',
+    '\x81', '\x82', '\x83', '\x84', '\x85', '\x86', '\x87', '\x88',
+    '\x89', '\x8a', '\x8b', '\x8c', '\x8d', '\x8e', '\x8f', '\x90',
+    '\x91', '\x92', '\x93', '\x94', '\x95', '\x96', '\x97', '\x98',
+    '\x99', '\x9a', '\x9b', '\x9c', '\x9d', '\x9e', '\x9f', '\xa0',
+    '\xa1', '\xa2', '\xa3', '\xa4', '\xa5', '\xa6', '\xa7', '\xa8',
+    '\xa9', '\xaa', '\xab', '\xac', '\xad', '\xae', '\xaf', '\xb0',
+    '\xb1', '\xb2', '\xb3', '\xb4', '\xb5', '\xb6', '\xb7', '\xb8',
+    '\xb9', '\xba', '\xbb', '\xbc', '\xbd', '\xbe', '\xbf', '\xc0',
+    '\xc1', '\xc2', '\xc3', '\xc4', '\xc5', '\xc6', '\xc7', '\xc8',
+    '\xc9', '\xca', '\xcb', '\xcc', '\xcd', '\xce', '\xcf', '\xd0',
+    '\xd1', '\xd2', '\xd3', '\xd4', '\xd5', '\xd6', '\xd7', '\xd8',
+    '\xd9', '\xda', '\xdb', '\xdc', '\xdd', '\xde', '\xdf', '\xe0',
+    '\xe1', '\xe2', '\xe3', '\xe4', '\xe5', '\xe6', '\xe7', '\xe8',
+    '\xe9', '\xea', '\xeb', '\xec', '\xed', '\xee', '\xef', '\xf0',
+    '\xf1', '\xf2', '\xf3', '\xf4', '\xf5', '\xf6', '\xf7', '\xf8',
+    '\xf9', '\xfa', '\xfb', '\xfc', '\xfd', '\xfe', '\xff',
+];
+