diff --git a/src/sql/engine/expr/ob_expr_lrpad.cpp b/src/sql/engine/expr/ob_expr_lrpad.cpp
index 283bde2bef..bd8d9f7076 100644
--- a/src/sql/engine/expr/ob_expr_lrpad.cpp
+++ b/src/sql/engine/expr/ob_expr_lrpad.cpp
@@ -198,11 +198,35 @@ int ObExprBaseLRpad::calc_type_length_oracle(const ObExprResType &result_type,
   return ret;
 }
 
+int ObExprBaseLRpad::get_origin_len_obj(ObObj &len_obj) const
+{
+  int ret = OB_SUCCESS;
+  ObRawExpr *expr = NULL;
+  if (OB_ISNULL(expr = get_raw_expr())) {
+    ret = OB_ERR_UNEXPECTED;
+    LOG_WARN("fail to get_raw_expr", K(ret));
+  } else if (expr->get_children_count() >= 2 && OB_NOT_NULL(expr = expr->get_param_expr(1))
+             && expr->get_expr_type() == T_FUN_SYS_CAST && CM_IS_IMPLICIT_CAST(expr->get_extra())) {
+    do {
+      if (expr->get_children_count() >= 1
+          && OB_ISNULL(expr = expr->get_param_expr(0))) {
+        ret = OB_ERR_UNEXPECTED;
+        LOG_WARN("fail to get_param_expr", K(ret));
+      }
+    } while (OB_SUCC(ret) && T_FUN_SYS_CAST == expr->get_expr_type()
+             && CM_IS_IMPLICIT_CAST(expr->get_extra()));
+    if (OB_SUCC(ret)) {
+      len_obj = expr->get_result_type().get_param();
+    }
+  }
+  return ret;
+}
+
 int ObExprBaseLRpad::calc_type(ObExprResType &type,
                                ObExprResType &text,
                                ObExprResType &len,
                                ObExprResType *pad_text,
-                               ObExprTypeCtx &type_ctx)
+                               ObExprTypeCtx &type_ctx) const
 {
   int ret = OB_SUCCESS;
   ObObjType text_type = ObNullType;
@@ -248,9 +272,6 @@ int ObExprBaseLRpad::calc_type(ObExprResType &type,
     len.set_calc_type(len_type);
     if (is_mysql_mode()) {
       pad_obj = pad_text->get_param();
-      type.set_type(text_type);
-      text.set_calc_type(text_type);
-      pad_text->set_calc_type(text_type);
       ObSEArray<ObExprResType, 2> types;
       OZ(types.push_back(text));
       OZ(types.push_back(*pad_text));
@@ -258,6 +279,28 @@ int ObExprBaseLRpad::calc_type(ObExprResType &type,
                                               type_ctx.get_coll_type()));
       OX(text.set_calc_collation_type(type.get_collation_type()));
       OX(pad_text->set_calc_collation_type(type.get_collation_type()));
+      if (OB_SUCC(ret)) {
+        // len expr may add cast, search real len obj
+        if (OB_FAIL(get_origin_len_obj(length_obj))) {
+          LOG_WARN("fail to get ori len obj", K(ret));
+        } else if (!length_obj.is_null()) {
+          if (OB_FAIL(calc_type_length_mysql(type, text_obj, pad_obj, length_obj, type_ctx.get_session(), text_len))) {
+            LOG_WARN("failed to calc result type length mysql mode", K(ret));
+          }
+        } else {
+          text_len = max_len;
+        }
+        if (OB_SUCC(ret)) {
+          text_type = get_result_type_mysql(text_len);
+          type.set_type(text_type);
+          if (!ob_is_text_tc(text.get_type())) {
+            text.set_calc_type(text_type);
+          }
+          if (!ob_is_text_tc(pad_text->get_type())) {
+            pad_text->set_calc_type(text_type);
+          }
+        }
+      }
     } else {
       ObSEArray<ObExprResType*, 2> types;
       OZ(types.push_back(&text));
@@ -287,8 +330,6 @@ int ObExprBaseLRpad::calc_type(ObExprResType &type,
       if (!length_obj.is_null()) {
         if (is_oracle_mode && OB_FAIL(calc_type_length_oracle(type, text_obj, pad_obj, length_obj, text_len))) {
           LOG_WARN("failed to calc result type length oracle mode", K(ret));
-        } else if (!is_oracle_mode && OB_FAIL(calc_type_length_mysql(type, text_obj, pad_obj, length_obj, type_ctx.get_session(), text_len))) {
-          LOG_WARN("failed to calc result type length mysql mode", K(ret));
         }
       } else {
         text_len = max_len;
@@ -640,6 +681,7 @@ int ObExprBaseLRpad::calc_mysql_inner(const LRpadType pad_type,
   const ObCollationType cs_type = expr.datum_meta_.cs_type_;
   const ObObjType type = expr.datum_meta_.type_;
   bool has_lob_header = expr.obj_meta_.has_lob_header();
+  bool has_set_to_lob_locator = false;
   int64_t int_len = len.get_int();
   if (int_len < 0) {
     res.set_null();
@@ -652,28 +694,46 @@ int ObExprBaseLRpad::calc_mysql_inner(const LRpadType pad_type,
     // only substr needed
     result_size = ObCharset::charpos(cs_type, str_text.ptr(), str_text.length(), int_len);
     res.set_string(ObString(result_size, str_text.ptr()));
-  } else if (str_pad.length() == 0) {
-    res.set_string(ObString::make_empty_string());
-  } else if (OB_FAIL(get_padding_info_mysql(cs_type, str_text, int_len, str_pad,
-              max_result_size, repeat_count, prefix_size, result_size))) {
-    LOG_WARN("Failed to get padding info", K(ret), K(str_text), K(int_len),
-                                            K(str_pad), K(max_result_size));
-  } else if (result_size > max_result_size) {
-    res.set_null();
-    if (pad_type == RPAD_TYPE) {
-      LOG_USER_WARN(OB_ERR_FUNC_RESULT_TOO_LARGE, "rpad", static_cast<int>(max_result_size));
-    } else {
-      LOG_USER_WARN(OB_ERR_FUNC_RESULT_TOO_LARGE, "lpad", static_cast<int>(max_result_size));
-    }
-  } else if (OB_FAIL(padding(pad_type, cs_type, str_text.ptr(), str_text.length(), str_pad.ptr(),
-                              str_pad.length(), prefix_size, repeat_count, false, &res_alloc,
-                              result_ptr, result_size, type, has_lob_header))) {
-    LOG_WARN("Failed to pad", K(ret), K(str_text), K(str_pad), K(prefix_size), K(repeat_count));
   } else {
-    if (NULL == result_ptr || 0 == result_size) {
+    has_set_to_lob_locator = true;
+    if (str_pad.length() == 0) {
+      res.set_string(ObString::make_empty_string());
+    } else if (OB_FAIL(get_padding_info_mysql(cs_type, str_text, int_len, str_pad,
+                max_result_size, repeat_count, prefix_size, result_size))) {
+      LOG_WARN("Failed to get padding info", K(ret), K(str_text), K(int_len),
+                                              K(str_pad), K(max_result_size));
+    } else if (result_size > max_result_size) {
       res.set_null();
+      if (pad_type == RPAD_TYPE) {
+        LOG_USER_WARN(OB_ERR_FUNC_RESULT_TOO_LARGE, "rpad", static_cast<int>(max_result_size));
+      } else {
+        LOG_USER_WARN(OB_ERR_FUNC_RESULT_TOO_LARGE, "lpad", static_cast<int>(max_result_size));
+      }
+    } else if (OB_FAIL(padding(pad_type, cs_type, str_text.ptr(), str_text.length(), str_pad.ptr(),
+                                str_pad.length(), prefix_size, repeat_count, false, &res_alloc,
+                                result_ptr, result_size, type, has_lob_header))) {
+      LOG_WARN("Failed to pad", K(ret), K(str_text), K(str_pad), K(prefix_size), K(repeat_count));
     } else {
-      res.set_string(result_ptr, result_size);
+      if (NULL == result_ptr || 0 == result_size) {
+        res.set_null();
+      } else {
+        res.set_string(result_ptr, result_size);
+      }
+    }
+  }
+  if (OB_SUCC(ret) && ob_is_text_tc(type) && !res.is_null() &&
+      has_lob_header && !has_set_to_lob_locator) {
+    ObString data = res.get_string();
+    ObTextStringResult result_buffer(type, has_lob_header, &res_alloc);
+    int64_t buffer_len = 0;
+    if (OB_FAIL(result_buffer.init(data.length()))) {
+      LOG_WARN("init stringtextbuffer failed", K(ret), K(data));
+    } else if (OB_FAIL(result_buffer.append(data))) {
+      LOG_WARN("temp lob lseek failed", K(ret));
+    } else {
+      ObString output;
+      result_buffer.get_result_buffer(output);
+      res.set_string(output);
     }
   }
   return ret;
diff --git a/src/sql/engine/expr/ob_expr_lrpad.h b/src/sql/engine/expr/ob_expr_lrpad.h
index df8bb27541..11ebe229e3 100644
--- a/src/sql/engine/expr/ob_expr_lrpad.h
+++ b/src/sql/engine/expr/ob_expr_lrpad.h
@@ -30,11 +30,11 @@ public:
 
   virtual ~ObExprBaseLRpad();
 
-  static int calc_type(ObExprResType &type,
-                       ObExprResType &text,
-                       ObExprResType &len,
-                       ObExprResType *pad_text,
-                       common::ObExprTypeCtx &type_ctx);
+  int calc_type(ObExprResType &type,
+                ObExprResType &text,
+                ObExprResType &len,
+                ObExprResType *pad_text,
+                common::ObExprTypeCtx &type_ctx) const;
 
   static int padding(LRpadType type,
                      const common::ObCollationType coll_type,
@@ -136,6 +136,7 @@ public:
   static int calc_oracle(LRpadType pad_type, const ObExpr &expr, const common::ObDatum &text,
                          const common::ObDatum &len, const common::ObDatum &pad_text,
                          common::ObIAllocator &res_alloc, ObDatum &res, bool &is_unchanged_clob);
+  int get_origin_len_obj(ObObj &len_obj) const;
 private:
   DISALLOW_COPY_AND_ASSIGN(ObExprBaseLRpad);
 };
diff --git a/src/sql/engine/expr/ob_expr_repeat.cpp b/src/sql/engine/expr/ob_expr_repeat.cpp
index 9a2bd382f8..8b068abf43 100644
--- a/src/sql/engine/expr/ob_expr_repeat.cpp
+++ b/src/sql/engine/expr/ob_expr_repeat.cpp
@@ -46,7 +46,9 @@ int ObExprRepeat::calc_result_type2(ObExprResType &type,
                                     ObExprTypeCtx &type_ctx) const
 {
   int ret = OB_SUCCESS;
-  text.set_calc_type(common::ObVarcharType);
+  if (!text.is_string_type()) {
+    text.set_calc_type(common::ObVarcharType);
+  }
   count.set_calc_type(common::ObIntType);
   // Set cast mode for %count parameter, truncate string to integer.
   type_ctx.set_cast_mode(type_ctx.get_cast_mode() | CM_STRING_INTEGER_TRUNC);
diff --git a/src/sql/engine/expr/ob_expr_space.cpp b/src/sql/engine/expr/ob_expr_space.cpp
index 3686b30a2f..3c0de8351f 100644
--- a/src/sql/engine/expr/ob_expr_space.cpp
+++ b/src/sql/engine/expr/ob_expr_space.cpp
@@ -26,7 +26,7 @@ namespace sql
 {
 using namespace common;
 ObExprSpace::ObExprSpace(ObIAllocator &alloc)
-  : ObFuncExprOperator(alloc, T_FUN_SYS_SPACE, N_SPACE, 1, VALID_FOR_GENERATED_COL, NOT_ROW_DIMENSION) {}
+  : ObStringExprOperator(alloc, T_FUN_SYS_SPACE, N_SPACE, 1, VALID_FOR_GENERATED_COL) {}
 
 inline int ObExprSpace::calc_result_type1(
     ObExprResType &type,
@@ -36,11 +36,41 @@ inline int ObExprSpace::calc_result_type1(
   int ret = OB_SUCCESS;
   // space is mysql only expr
   CK(lib::is_mysql_mode());
-
-  type.set_type(ObVarcharType);
+  ObObjType res_type = ObMaxType;
+  if (type1.is_null()) {
+    res_type = ObVarcharType;
+  } else if (type1.is_literal()) {
+    const ObObj &obj = type1.get_param();
+    ObArenaAllocator alloc(ObModIds::OB_SQL_RES_TYPE);
+    const ObDataTypeCastParams dtc_params =
+          ObBasicSessionInfo::create_dtc_params(type_ctx.get_session());
+    int64_t cur_time = 0;
+    ObCastMode cast_mode = CM_NONE;
+    if (OB_FAIL(ObSQLUtils::get_default_cast_mode(type_ctx.get_session(), cast_mode))) {
+      LOG_WARN("failed to get default cast mode", K(ret));
+    } else {
+      cast_mode |= CM_WARN_ON_FAIL;
+      ObCastCtx cast_ctx(
+          &alloc, &dtc_params, cur_time, cast_mode, CS_TYPE_INVALID);
+      int64_t count_val = 0;
+      EXPR_GET_INT64_V2(obj, count_val);
+      res_type = get_result_type_mysql(count_val);
+    }
+  } else {
+    res_type = ObLongTextType;
+  }
+  type.set_type(res_type);
   type.set_collation_level(type1.get_collation_level());
   type.set_collation_type(get_default_collation_type(type.get_type(), *type_ctx.get_session()));
-  type.set_length(OB_MAX_VARCHAR_LENGTH);
+  if (ObVarcharType == type.get_type()) {
+    type.set_length(MAX_CHAR_LENGTH_FOR_VARCAHR_RESULT);
+  } else if (ob_is_text_tc(type.get_type())) {
+    const int32_t mbmaxlen = 4;
+    const int32_t default_text_length =
+      ObAccuracy::DDL_DEFAULT_ACCURACY[type.get_type()].get_length() / mbmaxlen;
+    // need to set a correct length for text tc in mysql mode
+    type.set_length(default_text_length);
+  }
   type1.set_calc_type(ObIntType);
   // Set cast mode for parameter casting, truncate string to integer.
   type_ctx.set_cast_mode(type_ctx.get_cast_mode() | CM_STRING_INTEGER_TRUNC);
diff --git a/src/sql/engine/expr/ob_expr_space.h b/src/sql/engine/expr/ob_expr_space.h
index c7caf448e5..1dd25d0f3b 100644
--- a/src/sql/engine/expr/ob_expr_space.h
+++ b/src/sql/engine/expr/ob_expr_space.h
@@ -18,7 +18,7 @@ namespace oceanbase
 {
 namespace sql
 {
-class ObExprSpace : public ObFuncExprOperator
+class ObExprSpace : public ObStringExprOperator
 {
 public:
 
diff --git a/tools/deploy/mysql_test/test_suite/static_engine/r/mysql/expr_repeat.result b/tools/deploy/mysql_test/test_suite/static_engine/r/mysql/expr_repeat.result
index 599bcd63fb..6d956c5ab0 100644
--- a/tools/deploy/mysql_test/test_suite/static_engine/r/mysql/expr_repeat.result
+++ b/tools/deploy/mysql_test/test_suite/static_engine/r/mysql/expr_repeat.result
@@ -82,3 +82,17 @@ select repeat(1.414, 2);
 select repeat("abc", 200000000);
 ERROR HY000: Result of repeat() was larger than max_allowed_packet (4194304) - truncated
 
+drop table t2;
+create table t2 as select repeat('a', 512),repeat('a', 513),repeat('a',32767),repeat('a',32768),repeat('a',65535),repeat('a',65536) from dual;
+desc t2;
++-------------------+--------------+------+-----+---------+-------+
+| Field             | Type         | Null | Key | Default | Extra |
++-------------------+--------------+------+-----+---------+-------+
+| repeat('a', 512)  | varchar(512) | YES  |     | NULL    |       |
+| repeat('a', 513)  | text         | YES  |     | NULL    |       |
+| repeat('a',32767) | text         | YES  |     | NULL    |       |
+| repeat('a',32768) | text         | YES  |     | NULL    |       |
+| repeat('a',65535) | text         | YES  |     | NULL    |       |
+| repeat('a',65536) | longtext     | YES  |     | NULL    |       |
++-------------------+--------------+------+-----+---------+-------+
+drop table t2;
diff --git a/tools/deploy/mysql_test/test_suite/static_engine/t/expr_repeat.test b/tools/deploy/mysql_test/test_suite/static_engine/t/expr_repeat.test
index 7d7d04bb16..1bc0c7fefe 100644
--- a/tools/deploy/mysql_test/test_suite/static_engine/t/expr_repeat.test
+++ b/tools/deploy/mysql_test/test_suite/static_engine/t/expr_repeat.test
@@ -33,6 +33,12 @@ select repeat(1.414, 2);
 --error 1301
 select repeat("abc", 200000000);
 
+--error 0,1051
+drop table t2;
+create table t2 as select repeat('a', 512),repeat('a', 513),repeat('a',32767),repeat('a',32768),repeat('a',65535),repeat('a',65536) from dual;
+desc t2;
+drop table t2;
+
 --enable_warnings
 
 connection syscon;