diff --git a/src/share/schema/ob_schema_service_sql_impl.cpp b/src/share/schema/ob_schema_service_sql_impl.cpp
index c0ff882190..7ed246b01c 100644
--- a/src/share/schema/ob_schema_service_sql_impl.cpp
+++ b/src/share/schema/ob_schema_service_sql_impl.cpp
@@ -4408,47 +4408,59 @@ int ObSchemaServiceSQLImpl::fetch_tables(
   const int64_t snapshot_timestamp = schema_status.snapshot_timestamp_;
   const uint64_t exec_tenant_id = fill_exec_tenant_id(schema_status);
   const char *table_name = NULL;
+  int64_t start_time = ObTimeUtility::current_time();
   if (!check_inner_stat()) {
     ret = OB_NOT_INIT;
     LOG_WARN("check inner stat fail", K(ret));
-  } else if (OB_FAIL(ObSchemaUtils::get_all_table_history_name(exec_tenant_id,
-                                                               table_name,
-                                                               schema_service_))) {
-    LOG_WARN("fail to get all table name", K(ret), K(exec_tenant_id));
-  } else if (!is_increase_schema) {
-    if (OB_FAIL(sql.append_fmt(FETCH_ALL_TABLE_HISTORY_FULL_SCHEMA,
-                               table_name, table_name,
-                               fill_extract_tenant_id(schema_status, tenant_id),
-                               schema_version,
-                               fill_extract_schema_id(schema_status, OB_ALL_CORE_TABLE_TID)))) {
-      LOG_WARN("append sql failed", K(ret));
-    }
   } else {
-    if (OB_FAIL(sql.append_fmt(FETCH_ALL_TABLE_HISTORY_SQL3,
-                               table_name,
-                               fill_extract_tenant_id(schema_status, tenant_id)))) {
-      LOG_WARN("append sql failed", K(ret));
-    } else if (OB_FAIL(sql.append_fmt(" AND SCHEMA_VERSION <= %ld", schema_version))) {
-      LOG_WARN("append sql failed", K(ret));
-    } else if (OB_FAIL(sql.append_fmt(" AND table_id in"))) {
-      LOG_WARN("append failed", K(ret));
-    } else if (OB_FAIL(SQL_APPEND_SCHEMA_ID(table, schema_keys, schema_key_size, sql))) {
-      LOG_WARN("sql append table id failed", K(ret));
-    }
-  }
-  if (OB_SUCC(ret)) {
-    SMART_VAR(ObMySQLProxy::MySQLResult, res) {
-      DEFINE_SQL_CLIENT_RETRY_WEAK_WITH_SNAPSHOT(sql_client, snapshot_timestamp);
-      if (OB_FAIL(sql.append(" ORDER BY tenant_id desc, table_id desc, schema_version desc"))) {
-        LOG_WARN("sql append failed", K(ret));
-      } else if (OB_FAIL(sql_client_retry_weak.read(res, exec_tenant_id, sql.ptr()))) {
-        LOG_WARN("execute sql failed", K(ret), K(tenant_id), K(sql));
-      } else if (OB_UNLIKELY(NULL == (result = res.get_result()))) {
-        ret = OB_ERR_UNEXPECTED;
-        LOG_WARN("fail to get result. ", K(ret));
-      } else if (OB_FAIL(ObSchemaRetrieveUtils::retrieve_table_schema(tenant_id, *result, schema_array))) {
-        LOG_WARN("failed to retrieve table schema", K(ret));
+    ObTimeoutCtx ctx;
+    if (OB_FAIL(ObSchemaUtils::get_all_table_history_name(exec_tenant_id,
+                                                                 table_name,
+                                                                 schema_service_))) {
+      LOG_WARN("fail to get all table name", K(ret), K(exec_tenant_id));
+    } else if (!is_increase_schema) {
+      const char *tname = OB_ALL_TABLE_HISTORY_TNAME;
+      if (OB_FAIL(set_refresh_full_schema_timeout_ctx_(sql_client, tenant_id, tname, ctx))) {
+        LOG_WARN("fail to set refresh full schema timeout ctx", KR(ret), K(tenant_id), "tname", tname);
+      } else if (OB_FAIL(sql.append_fmt(FETCH_ALL_TABLE_HISTORY_FULL_SCHEMA,
+                                 table_name, table_name,
+                                 fill_extract_tenant_id(schema_status, tenant_id),
+                                 schema_version,
+                                 fill_extract_schema_id(schema_status, OB_ALL_CORE_TABLE_TID)))) {
+        LOG_WARN("append sql failed", K(ret));
       }
+    } else {
+      if (OB_FAIL(sql.append_fmt(FETCH_ALL_TABLE_HISTORY_SQL3,
+                                 table_name,
+                                 fill_extract_tenant_id(schema_status, tenant_id)))) {
+        LOG_WARN("append sql failed", K(ret));
+      } else if (OB_FAIL(sql.append_fmt(" AND SCHEMA_VERSION <= %ld", schema_version))) {
+        LOG_WARN("append sql failed", K(ret));
+      } else if (OB_FAIL(sql.append_fmt(" AND table_id in"))) {
+        LOG_WARN("append failed", K(ret));
+      } else if (OB_FAIL(SQL_APPEND_SCHEMA_ID(table, schema_keys, schema_key_size, sql))) {
+        LOG_WARN("sql append table id failed", K(ret));
+      }
+    }
+    if (OB_SUCC(ret)) {
+      SMART_VAR(ObMySQLProxy::MySQLResult, res) {
+        DEFINE_SQL_CLIENT_RETRY_WEAK_WITH_SNAPSHOT(sql_client, snapshot_timestamp);
+        if (OB_FAIL(sql.append(" ORDER BY tenant_id desc, table_id desc, schema_version desc"))) {
+          LOG_WARN("sql append failed", K(ret));
+        } else if (OB_FAIL(sql_client_retry_weak.read(res, exec_tenant_id, sql.ptr()))) {
+          LOG_WARN("execute sql failed", K(ret), K(tenant_id), K(sql));
+        } else if (OB_UNLIKELY(NULL == (result = res.get_result()))) {
+          ret = OB_ERR_UNEXPECTED;
+          LOG_WARN("fail to get result. ", K(ret));
+        } else if (OB_FAIL(ObSchemaRetrieveUtils::retrieve_table_schema(tenant_id, *result, schema_array))) {
+          LOG_WARN("failed to retrieve table schema", K(ret));
+        }
+      }
+    }
+    if (!is_increase_schema) {
+      FLOG_INFO("[REFRESH_SCHEMA] fetch all tables cost",
+                KR(ret), K(tenant_id),
+                "cost", ObTimeUtility::current_time() - start_time);
     }
   }
   if (OB_SUCC(ret)) {
@@ -4496,6 +4508,11 @@ int ObSchemaServiceSQLImpl::fetch_tables(
       }
     }
   }
+  if (!is_increase_schema) {
+    FLOG_INFO("[REFRESH_SCHEMA] fetch all simple tables cost",
+              KR(ret), K(tenant_id),
+              "cost", ObTimeUtility::current_time() - start_time);
+  }
   return ret;
 }
 
@@ -8716,6 +8733,89 @@ int ObSchemaServiceSQLImpl::try_mock_link_table_column(ObTableSchema &table_sche
   return ret;
 }
 
+// this timeout context will take effective when ObTimeoutCtx/THIS_WORKER.timeout is not set.
+int ObSchemaServiceSQLImpl::set_refresh_full_schema_timeout_ctx_(
+    ObISQLClient &sql_client,
+    const uint64_t tenant_id,
+    const char* tname,
+    ObTimeoutCtx &ctx)
+{
+  int ret = OB_SUCCESS;
+  int64_t timeout = 0;
+  if (OB_UNLIKELY(
+      OB_INVALID_TENANT_ID == tenant_id
+      || OB_ISNULL(tname))) {
+    ret = OB_INVALID_ARGUMENT;
+    LOG_WARN("invalid tenant_id or tname is empty", KR(ret), K(tenant_id), KP(tname));
+  } else if (OB_FAIL(calc_refresh_full_schema_timeout_ctx_(sql_client, tenant_id, tname, timeout))) {
+    LOG_WARN("fail to calc refresh full schema timeout", KR(ret), K(tenant_id), "tname", tname);
+  } else {
+    const int64_t ori_ctx_timeout = ctx.get_timeout();
+    const int64_t ori_worker_timeout = THIS_WORKER.get_timeout_ts();
+    if (OB_FAIL(ObShareUtil::set_default_timeout_ctx(ctx, timeout))) {
+      LOG_WARN("fail to set timeout ctx", KR(ret), K(timeout));
+    }
+    FLOG_INFO("[REFRESH_SCHEMA] try set refresh schema timeout ctx",
+               KR(ret), K(tenant_id),
+              "tname", tname,
+              K(ori_ctx_timeout),
+              K(ori_worker_timeout),
+              "calc_timeout", timeout,
+              "actual_timeout", ctx.get_timeout());
+  }
+  return ret;
+}
+
+int ObSchemaServiceSQLImpl::calc_refresh_full_schema_timeout_ctx_(
+    ObISQLClient &sql_client,
+    const uint64_t tenant_id,
+    const char* tname,
+    int64_t &timeout)
+{
+  int ret = OB_SUCCESS;
+  ObTimeoutCtx ctx;
+  timeout = 0;
+  int64_t start_time = ObTimeUtility::current_time();
+  SMART_VAR(ObMySQLProxy::MySQLResult, res) {
+    ObMySQLResult *result = NULL;
+    ObSqlString sql;
+    // consider that sql scan 10w records per scecond, and normally history table has 1000w records at most.
+    int64_t default_timeout = 4 * GCONF.internal_sql_execute_timeout;
+    if (OB_UNLIKELY(
+        OB_INVALID_TENANT_ID == tenant_id
+        || OB_ISNULL(tname))) {
+      ret = OB_INVALID_ARGUMENT;
+      LOG_WARN("invalid tenant_id or tname is empty", KR(ret), K(tenant_id), KP(tname));
+    } else if (OB_FAIL(ObShareUtil::set_default_timeout_ctx(ctx, default_timeout))) {
+      LOG_WARN("fail to set default timeout", KR(ret), K(default_timeout));
+    } else if (OB_FAIL(sql.assign_fmt("SELECT count(*) as count FROM %s", tname))) {
+      LOG_WARN("append sql failed", KR(ret), K(sql), "tname", tname);
+    } else if (OB_FAIL(sql_client.read(res, tenant_id, sql.ptr()))) {
+      LOG_WARN("execute sql failed", KR(ret), K(tenant_id), K(sql));
+    } else if (OB_ISNULL(result = res.get_result())) {
+      ret = OB_ERR_UNEXPECTED;
+      LOG_WARN("fail to get result. ", KR(ret));
+    } else if (OB_FAIL(result->next())) {
+      LOG_WARN("fail to get next row", KR(ret));
+    } else {
+      int64_t row_cnt = 0;
+      EXTRACT_INT_FIELD_MYSQL(*result, "count", row_cnt, int64_t);
+      if (OB_SUCC(ret)) {
+        // each 100w history may cost almost 400s (almost each 7w history may cost `internal_sql_execute_timeout`)
+        // for more details: ob/qa/gqk9w2
+        timeout = ((row_cnt / (70 * 1000L)) + 1) * GCONF.internal_sql_execute_timeout;
+        FLOG_INFO("[REFRESH_SCHEMA] calc refresh schema timeout",
+                   KR(ret), K(tenant_id),
+                   "tname", tname,
+                   K(row_cnt), K(timeout),
+                   "cost", ObTimeUtility::current_time() - start_time);
+      }
+    }
+  } // end SMTART_VAR
+  return ret;
+}
+
+
 }//namespace schema
 }//namespace share
 }//namespace oceanbase
diff --git a/src/share/schema/ob_schema_service_sql_impl.h b/src/share/schema/ob_schema_service_sql_impl.h
index d6c636b59c..675bab5728 100644
--- a/src/share/schema/ob_schema_service_sql_impl.h
+++ b/src/share/schema/ob_schema_service_sql_impl.h
@@ -975,6 +975,18 @@ private:
   int gen_leader_normal_schema_version(const uint64_t tenant_id,
                                        const int64_t refreshed_schema_version,
                                        int64_t &schema_version);
+
+  int set_refresh_full_schema_timeout_ctx_(
+      ObISQLClient &sql_client,
+      const uint64_t tenant_id,
+      const char* tname,
+      ObTimeoutCtx &ctx);
+
+  int calc_refresh_full_schema_timeout_ctx_(
+      ObISQLClient &sql_client,
+      const uint64_t tenant_id,
+      const char* tname,
+      int64_t &timeout);
 private:
   common::ObMySQLProxy *mysql_proxy_;
   common::ObDbLinkProxy *dblink_proxy_;