[TD-1002]<test> add test case for percentile function

tests/pytest/fulltest.sh

@@ -233,6 +233,7 @@ python3 ./test.py -f functions/function_top.py -r 1
 python3 ./test.py -f functions/function_twa.py -r 1
 python3 ./test.py -f functions/function_twa_test2.py
 python3 ./test.py -f functions/all_null_value.py
+python3 ./test.py -f functions/function_percentile2.py
 python3 queryCount.py
 python3 ./test.py -f query/queryGroupbyWithInterval.py
 python3 client/twoClients.py

tests/pytest/functions/function_percentile2.py

@@ -0,0 +1,57 @@
+###################################################################
+#           Copyright (c) 2016 by TAOS Technologies, Inc.
+#                     All rights reserved.
+#
+#  This file is proprietary and confidential to TAOS Technologies.
+#  No part of this file may be reproduced, stored, transmitted,
+#  disclosed or used in any form or by any means other than as
+#  expressly provided by the written permission from Jianhui Tao
+#
+###################################################################
+
+# -*- coding: utf-8 -*-
+
+from util.log import *
+from util.cases import *
+from util.sql import *
+import numpy as np
+
+
+class TDTestCase:
+    def init(self, conn, logSql):
+        tdLog.debug("start to execute %s" % __file__)
+        tdSql.init(conn.cursor())
+
+        self.rowNum = 1000000
+        self.ts = 1537146000000
+        
+    def run(self):
+        tdSql.prepare()
+
+        tdSql.execute("create table test(ts timestamp, col1 int, col2 float)")
+        for i in range(1000):
+            sql = "insert into test values"
+            batchSize = int (self.rowNum / 1000)            
+            for j in range (batchSize):                
+                currTime = self.ts + batchSize * i + j
+                sql += "(%d, 1, 2.37)" % currTime
+            tdSql.execute(sql)
+
+        tdSql.query("select percentile(col1, 20) from test")
+        tdSql.checkData(0, 0, 1)
+
+        tdSql.query("select percentile(col2, 20) from test")
+        tdSql.checkData(0, 0, 2.3699998)
+
+        tdSql.query("select apercentile(col1, 20) from test")
+        tdSql.checkData(0, 0, 1)
+
+        tdSql.query("select apercentile(col2, 20) from test")
+        tdSql.checkData(0, 0, 2.3699998)
+
+    def stop(self):
+        tdSql.close()
+        tdLog.success("%s successfully executed" % __file__)
+
+tdCases.addWindows(__file__, TDTestCase())
+tdCases.addLinux(__file__, TDTestCase())

tests/pytest/util/dnodes.py

@@ -136,7 +136,8 @@ class TDDnode:
             "monitorDebugFlag":"135",
             "udebugFlag":"135",
             "jnidebugFlag":"135",
-            "qdebugFlag":"135"
+            "qdebugFlag":"135",
+            "maxSQLLength":"1048576"
         }
 
     def init(self, path):