diff --git a/dbcon/mysql/ha_mcs_execplan.cpp b/dbcon/mysql/ha_mcs_execplan.cpp
index 334243a66..f0d042545 100644
--- a/dbcon/mysql/ha_mcs_execplan.cpp
+++ b/dbcon/mysql/ha_mcs_execplan.cpp
@@ -7674,6 +7674,514 @@ void buildInToExistsFilter(gp_walk_info& gwi, SELECT_LEX& select_lex)
   }
 }
 
+
+/*@brief  Process SELECT part of a query or sub-query      */
+/***********************************************************
+ * DESCRIPTION:
+ *  Processes SELECT part of a query or sub-query
+ * RETURNS
+ *  error id as an int
+ ***********************************************************/
+ int processSelect(SELECT_LEX& select_lex, gp_walk_info& gwi, SCSEP& csep, 
+   vector<Item_field*>& funcFieldVec,
+   CalpontSelectExecutionPlan::SelectList& selectSubList)
+ {
+    gwi.select_lex = &select_lex;
+ #ifdef DEBUG_WALK_COND
+   {
+     cerr << "------------------- SELECT --------------------" << endl;
+     List_iterator_fast<Item> it(select_lex.item_list);
+     Item* item;
+ 
+     while ((item = it++))
+     {
+       debug_walk(item, 0);
+     }
+ 
+     cerr << "-----------------------------------------------\n" << endl;
+   }
+ #endif
+ 
+   // analyze SELECT and ORDER BY parts - do they have implicit GROUP BY induced by aggregates?
+   {
+     if (select_lex.group_list.first)
+     {
+       // we have an explicit GROUP BY.
+       gwi.implicitExplicitGroupBy = true;
+     }
+     else
+     {
+       // do we have an implicit GROUP BY?
+       List_iterator_fast<Item> it(select_lex.item_list);
+       Item* item;
+ 
+       while ((item = it++))
+       {
+         analyzeForImplicitGroupBy(item, gwi);
+       }
+       SQL_I_List<ORDER> order_list = select_lex.order_list;
+       ORDER* ordercol = static_cast<ORDER*>(order_list.first);
+ 
+       for (; ordercol; ordercol = ordercol->next)
+       {
+         analyzeForImplicitGroupBy(*(ordercol->item), gwi);
+       }
+     }
+   }
+   // populate returnedcolumnlist and columnmap
+   List_iterator_fast<Item> it(select_lex.item_list);
+   Item* item;
+ 
+   // empty rcWorkStack and ptWorkStack. They should all be empty by now.
+   clearStacks(gwi, false, true);
+ 
+   // indicate the starting pos of scalar returned column, because some join column
+   // has been inserted to the returned column list.
+   if (gwi.subQuery)
+   {
+     ScalarSub* scalar = dynamic_cast<ScalarSub*>(gwi.subQuery);
+ 
+     if (scalar)
+       scalar->returnedColPos(gwi.additionalRetCols.size());
+   }
+ 
+ 
+   while ((item = it++))
+   {
+     string itemAlias = (item->name.length ? item->name.str : "<NULL>");
+ 
+     // @bug 5916. Need to keep checking until getting concret item in case
+     // of nested view.
+     Item* baseItem = item;
+     while (item->type() == Item::REF_ITEM)
+     {
+       Item_ref* ref = (Item_ref*)item;
+       item = (*(ref->ref));
+     }
+ 
+     Item::Type itype = item->type();
+ 
+     switch (itype)
+     {
+       case Item::FIELD_ITEM:
+       {
+         Item_field* ifp = (Item_field*)item;
+         SimpleColumn* sc = NULL;
+ 
+         if (ifp->field_name.length && string(ifp->field_name.str) == "*")
+         {
+           collectAllCols(gwi, ifp);
+           break;
+         }
+         sc = buildSimpleColumn(ifp, gwi);
+ 
+         if (sc)
+         {
+           string fullname;
+           String str;
+           ifp->print(&str, QT_ORDINARY);
+           fullname = str.c_ptr();
+ 
+           if (!ifp->is_explicit_name())  // no alias
+           {
+             sc->alias(fullname);
+           }
+           else  // alias
+           {
+             if (!itemAlias.empty())
+               sc->alias(itemAlias);
+           }
+ 
+           // We need to look into GROUP BY columns to decide if we need to wrap a column.
+           ReturnedColumn* rc = wrapIntoAggregate(sc, gwi, baseItem);
+ 
+           SRCP sprc(rc);
+           pushReturnedCol(gwi, baseItem, sprc);
+ 
+           gwi.columnMap.insert(
+               CalpontSelectExecutionPlan::ColumnMap::value_type(string(ifp->field_name.str), sprc));
+           TABLE_LIST* tmp = 0;
+ 
+           if (ifp->cached_table)
+             tmp = ifp->cached_table;
+ 
+           gwi.tableMap[make_aliastable(sc->schemaName(), sc->tableName(), sc->tableAlias(),
+                                        sc->isColumnStore())] = make_pair(1, tmp);
+         }
+         else
+         {
+           setError(gwi.thd, ER_INTERNAL_ERROR, gwi.parseErrorText, gwi);
+           delete sc;
+           return ER_INTERNAL_ERROR;
+         }
+ 
+         break;
+       }
+ 
+       // aggregate column
+       case Item::SUM_FUNC_ITEM:
+       {
+         ReturnedColumn* ac = buildAggregateColumn(item, gwi);
+ 
+         if (gwi.fatalParseError)
+         {
+           // e.g., non-support ref column
+           setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
+           delete ac;
+           return ER_CHECK_NOT_IMPLEMENTED;
+         }
+ 
+         // add this agg col to returnedColumnList
+         boost::shared_ptr<ReturnedColumn> spac(ac);
+         pushReturnedCol(gwi, item, spac);
+         break;
+       }
+ 
+       case Item::FUNC_ITEM:
+       {
+         Item_func* ifp = static_cast<Item_func*>(item);
+ 
+         // @bug4383. error out non-support stored function
+         if (ifp->functype() == Item_func::FUNC_SP)
+         {
+           gwi.fatalParseError = true;
+           gwi.parseErrorText = IDBErrorInfo::instance()->errorMsg(ERR_SP_FUNCTION_NOT_SUPPORT);
+           setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
+           return ER_CHECK_NOT_IMPLEMENTED;
+         }
+ 
+         if (string(ifp->func_name()) == "xor")
+         {
+           gwi.fatalParseError = true;
+           gwi.parseErrorText = IDBErrorInfo::instance()->errorMsg(ERR_FILTER_COND_EXP);
+           setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
+           return ER_CHECK_NOT_IMPLEMENTED;
+         }
+ 
+         uint16_t parseInfo = 0;
+         vector<Item_field*> tmpVec;
+         bool hasNonSupportItem = false;
+         parse_item(ifp, tmpVec, hasNonSupportItem, parseInfo, &gwi);
+ 
+         if (ifp->with_subquery() || string(ifp->func_name()) == string("<in_optimizer>") ||
+             ifp->functype() == Item_func::NOT_ALL_FUNC || parseInfo & SUB_BIT)
+         {
+           gwi.fatalParseError = true;
+           gwi.parseErrorText = IDBErrorInfo::instance()->errorMsg(ERR_NON_SUPPORT_SELECT_SUB);
+           setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
+           return ER_CHECK_NOT_IMPLEMENTED;
+         }
+ 
+         // if "IN" or "BETWEEN" are in the SELECT clause, build function column
+         string funcName = ifp->func_name();
+         ReturnedColumn* rc;
+         if (funcName == "in" || funcName == " IN " || funcName == "between")
+         {
+           rc = buildFunctionColumn(ifp, gwi, hasNonSupportItem, true);
+         }
+         else
+         {
+           rc = buildFunctionColumn(ifp, gwi, hasNonSupportItem);
+         }
+ 
+         SRCP srcp(rc);
+ 
+         if (rc)
+         {
+           // MCOL-2178 CS has to process determenistic functions with constant arguments.
+           if (!hasNonSupportItem && ifp->const_item() && !(parseInfo & AF_BIT) && tmpVec.size() == 0)
+           {
+             srcp.reset(buildReturnedColumn(item, gwi, gwi.fatalParseError));
+             pushReturnedCol(gwi, item, srcp);
+ 
+             if (ifp->name.length)
+               srcp->alias(ifp->name.str);
+ 
+             continue;
+           }
+           // FIXME: usage of pushReturnedCol instead of gwi.returnedCols.push_back(srcp) here
+           // made within MCOL-5776 produced bug MCOL-5932 so, the check of equal columns is disabled
+           pushReturnedCol(gwi, item, srcp);
+         }
+         else  // This was a vtable post-process block
+         {
+           hasNonSupportItem = false;
+           uint32_t before_size = funcFieldVec.size();
+           parse_item(ifp, funcFieldVec, hasNonSupportItem, parseInfo, &gwi);
+           uint32_t after_size = funcFieldVec.size();
+ 
+           // pushdown handler projection functions
+           // @bug3881. set_user_var can not be treated as constant function
+           // @bug5716. Try to avoid post process function for union query.
+           if (!hasNonSupportItem && (after_size - before_size) == 0 && !(parseInfo & AGG_BIT) &&
+               !(parseInfo & SUB_BIT))
+           {
+             ConstantColumn* cc = buildConstantColumnMaybeNullUsingValStr(ifp, gwi);
+ 
+             SRCP srcp(cc);
+ 
+             if (ifp->name.length)
+               cc->alias(ifp->name.str);
+ 
+             pushReturnedCol(gwi, ifp, srcp);
+ 
+             // clear the error set by buildFunctionColumn
+             gwi.fatalParseError = false;
+             gwi.parseErrorText = "";
+             break;
+           }
+           else if (hasNonSupportItem || parseInfo & AGG_BIT || parseInfo & SUB_BIT ||
+                    (gwi.fatalParseError && gwi.subQuery))
+           {
+             if (gwi.parseErrorText.empty())
+             {
+               Message::Args args;
+               args.add(ifp->func_name());
+               gwi.parseErrorText = IDBErrorInfo::instance()->errorMsg(ERR_NON_SUPPORTED_FUNCTION, args);
+             }
+ 
+             setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
+             return ER_CHECK_NOT_IMPLEMENTED;
+           }
+           else if (gwi.subQuery && (isPredicateFunction(ifp, &gwi) || ifp->type() == Item::COND_ITEM))
+           {
+             gwi.fatalParseError = true;
+             gwi.parseErrorText = IDBErrorInfo::instance()->errorMsg(ERR_FILTER_COND_EXP);
+             setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
+             return ER_CHECK_NOT_IMPLEMENTED;
+           }
+ 
+           //@Bug 3030 Add error check for dml statement
+           if (ha_mcs_common::isUpdateOrDeleteStatement(gwi.thd->lex->sql_command))
+           {
+             if (after_size - before_size != 0)
+             {
+               gwi.parseErrorText = ifp->func_name();
+               return -1;
+             }
+           }
+           else
+           {
+             Message::Args args;
+             args.add(ifp->func_name());
+             gwi.parseErrorText = IDBErrorInfo::instance()->errorMsg(ERR_NON_SUPPORTED_FUNCTION, args);
+             setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
+             return ER_CHECK_NOT_IMPLEMENTED;
+           }
+         }
+ 
+         break;
+       }  // End of FUNC_ITEM
+ 
+       // DRRTUY Replace the whole section with typeid() checks or use
+       // static_cast here
+       case Item::CONST_ITEM:
+       {
+         switch (item->cmp_type())
+ 
+         {
+           case INT_RESULT:
+           case STRING_RESULT:
+           case DECIMAL_RESULT:
+           case REAL_RESULT:
+           case TIME_RESULT:
+           {
+             if (ha_mcs_common::isUpdateOrDeleteStatement(gwi.thd->lex->sql_command))
+             {
+             }
+             else
+             {
+               // do not push the dummy column (mysql added) to returnedCol
+               if (item->name.length && string(item->name.str) == "Not_used")
+                 continue;
+ 
+               // @bug3509. Constant column is sent to ExeMgr now.
+               SRCP srcp(buildReturnedColumn(item, gwi, gwi.fatalParseError));
+ 
+               if (item->name.length)
+                 srcp->alias(item->name.str);
+ 
+               pushReturnedCol(gwi, item, srcp);
+             }
+ 
+             break;
+           }
+           // MCOL-2178 This switch doesn't handl
+           // ROW_
+           default:
+           {
+             IDEBUG(cerr << "Warning unsupported cmp_type() in projection" << endl);
+             // noop
+           }
+         }
+         break;
+       }  // CONST_ITEM ends here
+ 
+       case Item::NULL_ITEM:
+       {
+         if (ha_mcs_common::isUpdateOrDeleteStatement(gwi.thd->lex->sql_command))
+         {
+         }
+         else
+         {
+           SRCP srcp(buildReturnedColumn(item, gwi, gwi.fatalParseError));
+           pushReturnedCol(gwi, item, srcp);
+ 
+           if (item->name.length)
+             srcp->alias(item->name.str);
+         }
+ 
+         break;
+       }
+ 
+       case Item::SUBSELECT_ITEM:
+       {
+         Item_subselect* sub = (Item_subselect*)item;
+ 
+         if (sub->substype() != Item_subselect::SINGLEROW_SUBS)
+         {
+           gwi.fatalParseError = true;
+           gwi.parseErrorText = IDBErrorInfo::instance()->errorMsg(ERR_NON_SUPPORT_SELECT_SUB);
+           setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
+           return ER_CHECK_NOT_IMPLEMENTED;
+         }
+ 
+ #ifdef DEBUG_WALK_COND
+         cerr << "SELECT clause SUBSELECT Item: " << sub->substype() << endl;
+         JOIN* join = sub->get_select_lex()->join;
+ 
+         if (join)
+         {
+           Item_cond* cond = static_cast<Item_cond*>(join->conds);
+ 
+           if (cond)
+             cond->traverse_cond(debug_walk, &gwi, Item::POSTFIX);
+         }
+ 
+         cerr << "Finish SELECT clause subselect item traversing" << endl;
+ #endif
+         SelectSubQuery* selectSub = new SelectSubQuery(gwi, sub);
+         // selectSub->gwip(&gwi);
+         SCSEP ssub = selectSub->transform();
+ 
+         if (!ssub || gwi.fatalParseError)
+         {
+           if (gwi.parseErrorText.empty())
+             gwi.parseErrorText = "Unsupported Item in SELECT subquery.";
+ 
+           setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
+ 
+           return ER_CHECK_NOT_IMPLEMENTED;
+         }
+ 
+         selectSubList.push_back(ssub);
+         SimpleColumn* rc = new SimpleColumn();
+         rc->colSource(rc->colSource() | SELECT_SUB);
+         rc->timeZone(gwi.timeZone);
+ 
+         if (sub->get_select_lex()->get_table_list())
+         {
+           rc->viewName(getViewName(sub->get_select_lex()->get_table_list()), lower_case_table_names);
+         }
+         if (sub->name.length)
+           rc->alias(sub->name.str);
+ 
+         gwi.returnedCols.push_back(SRCP(rc));
+ 
+         break;
+       }
+ 
+       case Item::COND_ITEM:
+       {
+         gwi.fatalParseError = true;
+         gwi.parseErrorText = IDBErrorInfo::instance()->errorMsg(ERR_FILTER_COND_EXP);
+         setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
+         return ER_CHECK_NOT_IMPLEMENTED;
+       }
+ 
+       case Item::EXPR_CACHE_ITEM:
+       {
+         printf("EXPR_CACHE_ITEM in getSelectPlan\n");
+         gwi.fatalParseError = true;
+         gwi.parseErrorText = IDBErrorInfo::instance()->errorMsg(ERR_UNKNOWN_COL);
+         setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
+         return ER_CHECK_NOT_IMPLEMENTED;
+       }
+ 
+       case Item::WINDOW_FUNC_ITEM:
+       {
+         SRCP srcp(buildWindowFunctionColumn(item, gwi, gwi.fatalParseError));
+ 
+         if (!srcp || gwi.fatalParseError)
+         {
+           if (gwi.parseErrorText.empty())
+             gwi.parseErrorText = "Unsupported Item in SELECT subquery.";
+ 
+           setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
+           return ER_CHECK_NOT_IMPLEMENTED;
+         }
+ 
+         pushReturnedCol(gwi, item, srcp);
+         break;
+       }
+       case Item::TYPE_HOLDER:
+       {
+         if (!gwi.tbList.size())
+         {
+           gwi.parseErrorText = "subquery with VALUES";
+           gwi.fatalParseError = true;
+           setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
+           return ER_CHECK_NOT_IMPLEMENTED;
+         }
+         else
+         {
+           std::cerr << "********** received TYPE_HOLDER *********" << std::endl;
+         }
+         break;
+       }
+ 
+       default:
+       {
+         break;
+       }
+     }
+   }
+ 
+   // @bug4388 normalize the project coltypes for union main select list
+   if (!csep->unionVec().empty())
+   {
+     unsigned int unionedTypeRc = 0;
+ 
+     for (uint32_t i = 0; i < gwi.returnedCols.size(); i++)
+     {
+       vector<CalpontSystemCatalog::ColType> coltypes;
+ 
+       for (uint32_t j = 0; j < csep->unionVec().size(); j++)
+       {
+         CalpontSelectExecutionPlan* unionCsep =
+             dynamic_cast<CalpontSelectExecutionPlan*>(csep->unionVec()[j].get());
+         coltypes.push_back(unionCsep->returnedCols()[i]->resultType());
+ 
+         // @bug5976. set hasAggregate true for the main column if
+         // one corresponding union column has aggregate
+         if (unionCsep->returnedCols()[i]->hasAggregate())
+           gwi.returnedCols[i]->hasAggregate(true);
+       }
+ 
+       gwi.returnedCols[i]->resultType(
+           CalpontSystemCatalog::ColType::convertUnionColType(coltypes, unionedTypeRc));
+ 
+       if (unionedTypeRc != 0)
+       {
+         gwi.parseErrorText = IDBErrorInfo::instance()->errorMsg(unionedTypeRc);
+         setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
+         return ER_CHECK_NOT_IMPLEMENTED;
+       }
+     }
+   }
+   return 0;
+ }
+
 /*@brief  Translates SELECT_LEX into CSEP                  */
 /***********************************************************
  * DESCRIPTION:
@@ -7724,501 +8232,13 @@ int getSelectPlan(gp_walk_info& gwi, SELECT_LEX& select_lex, SCSEP& csep, bool i
   }
 
   gwi.clauseType = SELECT;
-  SELECT_LEX* oldSelectLex = gwi.select_lex;  // XXX: SZ: should it be restored in case of error return?
-  gwi.select_lex = &select_lex;
-#ifdef DEBUG_WALK_COND
-  {
-    cerr << "------------------- SELECT --------------------" << endl;
-    List_iterator_fast<Item> it(select_lex.item_list);
-    Item* item;
-
-    while ((item = it++))
-    {
-      debug_walk(item, 0);
-    }
-
-    cerr << "-----------------------------------------------\n" << endl;
-  }
-#endif
-
-  // analyze SELECT and ORDER BY parts - do they have implicit GROUP BY induced by aggregates?
-  {
-    if (select_lex.group_list.first)
-    {
-      // we have an explicit GROUP BY.
-      gwi.implicitExplicitGroupBy = true;
-    }
-    else
-    {
-      // do we have an implicit GROUP BY?
-      List_iterator_fast<Item> it(select_lex.item_list);
-      Item* item;
-
-      while ((item = it++))
-      {
-        analyzeForImplicitGroupBy(item, gwi);
-      }
-      SQL_I_List<ORDER> order_list = select_lex.order_list;
-      ORDER* ordercol = static_cast<ORDER*>(order_list.first);
-
-      for (; ordercol; ordercol = ordercol->next)
-      {
-        analyzeForImplicitGroupBy(*(ordercol->item), gwi);
-      }
-    }
-  }
-  // populate returnedcolumnlist and columnmap
-  List_iterator_fast<Item> it(select_lex.item_list);
-  Item* item;
+  SELECT_LEX* originalSelectLex = gwi.select_lex;  // XXX: SZ: should it be restored in case of error return?
   vector<Item_field*> funcFieldVec;
-
-  // empty rcWorkStack and ptWorkStack. They should all be empty by now.
-  clearStacks(gwi, false, true);
-
-  // indicate the starting pos of scalar returned column, because some join column
-  // has been inserted to the returned column list.
-  if (gwi.subQuery)
-  {
-    ScalarSub* scalar = dynamic_cast<ScalarSub*>(gwi.subQuery);
-
-    if (scalar)
-      scalar->returnedColPos(gwi.additionalRetCols.size());
-  }
-
   CalpontSelectExecutionPlan::SelectList selectSubList;
 
-  while ((item = it++))
+  if ((rc = processSelect(select_lex, gwi, csep, funcFieldVec, selectSubList)))
   {
-    string itemAlias = (item->name.length ? item->name.str : "<NULL>");
-
-    // @bug 5916. Need to keep checking until getting concret item in case
-    // of nested view.
-    Item* baseItem = item;
-    while (item->type() == Item::REF_ITEM)
-    {
-      Item_ref* ref = (Item_ref*)item;
-      item = (*(ref->ref));
-    }
-
-    Item::Type itype = item->type();
-
-    switch (itype)
-    {
-      case Item::FIELD_ITEM:
-      {
-        Item_field* ifp = (Item_field*)item;
-        SimpleColumn* sc = NULL;
-
-        if (ifp->field_name.length && string(ifp->field_name.str) == "*")
-        {
-          collectAllCols(gwi, ifp);
-          break;
-        }
-        sc = buildSimpleColumn(ifp, gwi);
-
-        if (sc)
-        {
-          string fullname;
-          String str;
-          ifp->print(&str, QT_ORDINARY);
-          fullname = str.c_ptr();
-
-          if (!ifp->is_explicit_name())  // no alias
-          {
-            sc->alias(fullname);
-          }
-          else  // alias
-          {
-            if (!itemAlias.empty())
-              sc->alias(itemAlias);
-          }
-
-          // We need to look into GROUP BY columns to decide if we need to wrap a column.
-          ReturnedColumn* rc = wrapIntoAggregate(sc, gwi, baseItem);
-
-          SRCP sprc(rc);
-          pushReturnedCol(gwi, baseItem, sprc);
-
-          gwi.columnMap.insert(
-              CalpontSelectExecutionPlan::ColumnMap::value_type(string(ifp->field_name.str), sprc));
-          TABLE_LIST* tmp = 0;
-
-          if (ifp->cached_table)
-            tmp = ifp->cached_table;
-
-          gwi.tableMap[make_aliastable(sc->schemaName(), sc->tableName(), sc->tableAlias(),
-                                       sc->isColumnStore())] = make_pair(1, tmp);
-        }
-        else
-        {
-          setError(gwi.thd, ER_INTERNAL_ERROR, gwi.parseErrorText, gwi);
-          delete sc;
-          return ER_INTERNAL_ERROR;
-        }
-
-        break;
-      }
-
-      // aggregate column
-      case Item::SUM_FUNC_ITEM:
-      {
-        ReturnedColumn* ac = buildAggregateColumn(item, gwi);
-
-        if (gwi.fatalParseError)
-        {
-          // e.g., non-support ref column
-          setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
-          delete ac;
-          return ER_CHECK_NOT_IMPLEMENTED;
-        }
-
-        // add this agg col to returnedColumnList
-        boost::shared_ptr<ReturnedColumn> spac(ac);
-        pushReturnedCol(gwi, item, spac);
-        break;
-      }
-
-      case Item::FUNC_ITEM:
-      {
-        Item_func* ifp = static_cast<Item_func*>(item);
-
-        // @bug4383. error out non-support stored function
-        if (ifp->functype() == Item_func::FUNC_SP)
-        {
-          gwi.fatalParseError = true;
-          gwi.parseErrorText = IDBErrorInfo::instance()->errorMsg(ERR_SP_FUNCTION_NOT_SUPPORT);
-          setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
-          return ER_CHECK_NOT_IMPLEMENTED;
-        }
-
-        if (string(ifp->func_name()) == "xor")
-        {
-          gwi.fatalParseError = true;
-          gwi.parseErrorText = IDBErrorInfo::instance()->errorMsg(ERR_FILTER_COND_EXP);
-          setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
-          return ER_CHECK_NOT_IMPLEMENTED;
-        }
-
-        uint16_t parseInfo = 0;
-        vector<Item_field*> tmpVec;
-        bool hasNonSupportItem = false;
-        parse_item(ifp, tmpVec, hasNonSupportItem, parseInfo, &gwi);
-
-        if (ifp->with_subquery() || string(ifp->func_name()) == string("<in_optimizer>") ||
-            ifp->functype() == Item_func::NOT_ALL_FUNC || parseInfo & SUB_BIT)
-        {
-          gwi.fatalParseError = true;
-          gwi.parseErrorText = IDBErrorInfo::instance()->errorMsg(ERR_NON_SUPPORT_SELECT_SUB);
-          setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
-          return ER_CHECK_NOT_IMPLEMENTED;
-        }
-
-        // if "IN" or "BETWEEN" are in the SELECT clause, build function column
-        string funcName = ifp->func_name();
-        ReturnedColumn* rc;
-        if (funcName == "in" || funcName == " IN " || funcName == "between")
-        {
-          rc = buildFunctionColumn(ifp, gwi, hasNonSupportItem, true);
-        }
-        else
-        {
-          rc = buildFunctionColumn(ifp, gwi, hasNonSupportItem);
-        }
-
-        SRCP srcp(rc);
-
-        if (rc)
-        {
-          // MCOL-2178 CS has to process determenistic functions with constant arguments.
-          if (!hasNonSupportItem && ifp->const_item() && !(parseInfo & AF_BIT) && tmpVec.size() == 0)
-          {
-            srcp.reset(buildReturnedColumn(item, gwi, gwi.fatalParseError));
-            pushReturnedCol(gwi, item, srcp);
-
-            if (ifp->name.length)
-              srcp->alias(ifp->name.str);
-
-            continue;
-          }
-          // FIXME: usage of pushReturnedCol instead of gwi.returnedCols.push_back(srcp) here
-          // made within MCOL-5776 produced bug MCOL-5932 so, the check of equal columns is disabled
-          pushReturnedCol(gwi, item, srcp);
-        }
-        else  // This was a vtable post-process block
-        {
-          hasNonSupportItem = false;
-          uint32_t before_size = funcFieldVec.size();
-          parse_item(ifp, funcFieldVec, hasNonSupportItem, parseInfo, &gwi);
-          uint32_t after_size = funcFieldVec.size();
-
-          // pushdown handler projection functions
-          // @bug3881. set_user_var can not be treated as constant function
-          // @bug5716. Try to avoid post process function for union query.
-          if (!hasNonSupportItem && (after_size - before_size) == 0 && !(parseInfo & AGG_BIT) &&
-              !(parseInfo & SUB_BIT))
-          {
-            ConstantColumn* cc = buildConstantColumnMaybeNullUsingValStr(ifp, gwi);
-
-            SRCP srcp(cc);
-
-            if (ifp->name.length)
-              cc->alias(ifp->name.str);
-
-            pushReturnedCol(gwi, ifp, srcp);
-
-            // clear the error set by buildFunctionColumn
-            gwi.fatalParseError = false;
-            gwi.parseErrorText = "";
-            break;
-          }
-          else if (hasNonSupportItem || parseInfo & AGG_BIT || parseInfo & SUB_BIT ||
-                   (gwi.fatalParseError && gwi.subQuery))
-          {
-            if (gwi.parseErrorText.empty())
-            {
-              Message::Args args;
-              args.add(ifp->func_name());
-              gwi.parseErrorText = IDBErrorInfo::instance()->errorMsg(ERR_NON_SUPPORTED_FUNCTION, args);
-            }
-
-            setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
-            return ER_CHECK_NOT_IMPLEMENTED;
-          }
-          else if (gwi.subQuery && (isPredicateFunction(ifp, &gwi) || ifp->type() == Item::COND_ITEM))
-          {
-            gwi.fatalParseError = true;
-            gwi.parseErrorText = IDBErrorInfo::instance()->errorMsg(ERR_FILTER_COND_EXP);
-            setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
-            return ER_CHECK_NOT_IMPLEMENTED;
-          }
-
-          //@Bug 3030 Add error check for dml statement
-          if (ha_mcs_common::isUpdateOrDeleteStatement(gwi.thd->lex->sql_command))
-          {
-            if (after_size - before_size != 0)
-            {
-              gwi.parseErrorText = ifp->func_name();
-              return -1;
-            }
-          }
-          else
-          {
-            Message::Args args;
-            args.add(ifp->func_name());
-            gwi.parseErrorText = IDBErrorInfo::instance()->errorMsg(ERR_NON_SUPPORTED_FUNCTION, args);
-            setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
-            return ER_CHECK_NOT_IMPLEMENTED;
-          }
-        }
-
-        break;
-      }  // End of FUNC_ITEM
-
-      // DRRTUY Replace the whole section with typeid() checks or use
-      // static_cast here
-      case Item::CONST_ITEM:
-      {
-        switch (item->cmp_type())
-
-        {
-          case INT_RESULT:
-          case STRING_RESULT:
-          case DECIMAL_RESULT:
-          case REAL_RESULT:
-          case TIME_RESULT:
-          {
-            if (ha_mcs_common::isUpdateOrDeleteStatement(gwi.thd->lex->sql_command))
-            {
-            }
-            else
-            {
-              // do not push the dummy column (mysql added) to returnedCol
-              if (item->name.length && string(item->name.str) == "Not_used")
-                continue;
-
-              // @bug3509. Constant column is sent to ExeMgr now.
-              SRCP srcp(buildReturnedColumn(item, gwi, gwi.fatalParseError));
-
-              if (item->name.length)
-                srcp->alias(item->name.str);
-
-              pushReturnedCol(gwi, item, srcp);
-            }
-
-            break;
-          }
-          // MCOL-2178 This switch doesn't handl
-          // ROW_
-          default:
-          {
-            IDEBUG(cerr << "Warning unsupported cmp_type() in projection" << endl);
-            // noop
-          }
-        }
-        break;
-      }  // CONST_ITEM ends here
-
-      case Item::NULL_ITEM:
-      {
-        if (ha_mcs_common::isUpdateOrDeleteStatement(gwi.thd->lex->sql_command))
-        {
-        }
-        else
-        {
-          SRCP srcp(buildReturnedColumn(item, gwi, gwi.fatalParseError));
-          pushReturnedCol(gwi, item, srcp);
-
-          if (item->name.length)
-            srcp->alias(item->name.str);
-        }
-
-        break;
-      }
-
-      case Item::SUBSELECT_ITEM:
-      {
-        Item_subselect* sub = (Item_subselect*)item;
-
-        if (sub->substype() != Item_subselect::SINGLEROW_SUBS)
-        {
-          gwi.fatalParseError = true;
-          gwi.parseErrorText = IDBErrorInfo::instance()->errorMsg(ERR_NON_SUPPORT_SELECT_SUB);
-          setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
-          return ER_CHECK_NOT_IMPLEMENTED;
-        }
-
-#ifdef DEBUG_WALK_COND
-        cerr << "SELECT clause SUBSELECT Item: " << sub->substype() << endl;
-        JOIN* join = sub->get_select_lex()->join;
-
-        if (join)
-        {
-          Item_cond* cond = static_cast<Item_cond*>(join->conds);
-
-          if (cond)
-            cond->traverse_cond(debug_walk, &gwi, Item::POSTFIX);
-        }
-
-        cerr << "Finish SELECT clause subselect item traversing" << endl;
-#endif
-        SelectSubQuery* selectSub = new SelectSubQuery(gwi, sub);
-        // selectSub->gwip(&gwi);
-        SCSEP ssub = selectSub->transform();
-
-        if (!ssub || gwi.fatalParseError)
-        {
-          if (gwi.parseErrorText.empty())
-            gwi.parseErrorText = "Unsupported Item in SELECT subquery.";
-
-          setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
-
-          return ER_CHECK_NOT_IMPLEMENTED;
-        }
-
-        selectSubList.push_back(ssub);
-        SimpleColumn* rc = new SimpleColumn();
-        rc->colSource(rc->colSource() | SELECT_SUB);
-        rc->timeZone(gwi.timeZone);
-
-        if (sub->get_select_lex()->get_table_list())
-        {
-          rc->viewName(getViewName(sub->get_select_lex()->get_table_list()), lower_case_table_names);
-        }
-        if (sub->name.length)
-          rc->alias(sub->name.str);
-
-        gwi.returnedCols.push_back(SRCP(rc));
-
-        break;
-      }
-
-      case Item::COND_ITEM:
-      {
-        gwi.fatalParseError = true;
-        gwi.parseErrorText = IDBErrorInfo::instance()->errorMsg(ERR_FILTER_COND_EXP);
-        setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
-        return ER_CHECK_NOT_IMPLEMENTED;
-      }
-
-      case Item::EXPR_CACHE_ITEM:
-      {
-        printf("EXPR_CACHE_ITEM in getSelectPlan\n");
-        gwi.fatalParseError = true;
-        gwi.parseErrorText = IDBErrorInfo::instance()->errorMsg(ERR_UNKNOWN_COL);
-        setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
-        return ER_CHECK_NOT_IMPLEMENTED;
-      }
-
-      case Item::WINDOW_FUNC_ITEM:
-      {
-        SRCP srcp(buildWindowFunctionColumn(item, gwi, gwi.fatalParseError));
-
-        if (!srcp || gwi.fatalParseError)
-        {
-          if (gwi.parseErrorText.empty())
-            gwi.parseErrorText = "Unsupported Item in SELECT subquery.";
-
-          setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
-          return ER_CHECK_NOT_IMPLEMENTED;
-        }
-
-        pushReturnedCol(gwi, item, srcp);
-        break;
-      }
-      case Item::TYPE_HOLDER:
-      {
-        if (!gwi.tbList.size())
-        {
-          gwi.parseErrorText = "subquery with VALUES";
-          gwi.fatalParseError = true;
-          setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
-          return ER_CHECK_NOT_IMPLEMENTED;
-        }
-        else
-        {
-          std::cerr << "********** received TYPE_HOLDER *********" << std::endl;
-        }
-        break;
-      }
-
-      default:
-      {
-        break;
-      }
-    }
-  }
-
-  // @bug4388 normalize the project coltypes for union main select list
-  if (!csep->unionVec().empty())
-  {
-    unsigned int unionedTypeRc = 0;
-
-    for (uint32_t i = 0; i < gwi.returnedCols.size(); i++)
-    {
-      vector<CalpontSystemCatalog::ColType> coltypes;
-
-      for (uint32_t j = 0; j < csep->unionVec().size(); j++)
-      {
-        CalpontSelectExecutionPlan* unionCsep =
-            dynamic_cast<CalpontSelectExecutionPlan*>(csep->unionVec()[j].get());
-        coltypes.push_back(unionCsep->returnedCols()[i]->resultType());
-
-        // @bug5976. set hasAggregate true for the main column if
-        // one corresponding union column has aggregate
-        if (unionCsep->returnedCols()[i]->hasAggregate())
-          gwi.returnedCols[i]->hasAggregate(true);
-      }
-
-      gwi.returnedCols[i]->resultType(
-          CalpontSystemCatalog::ColType::convertUnionColType(coltypes, unionedTypeRc));
-
-      if (unionedTypeRc != 0)
-      {
-        gwi.parseErrorText = IDBErrorInfo::instance()->errorMsg(unionedTypeRc);
-        setError(gwi.thd, ER_CHECK_NOT_IMPLEMENTED, gwi.parseErrorText, gwi);
-        return ER_CHECK_NOT_IMPLEMENTED;
-      }
-    }
+    return rc;
   }
 
   // Having clause handling
@@ -8994,7 +9014,7 @@ int getSelectPlan(gp_walk_info& gwi, SELECT_LEX& select_lex, SCSEP& csep, bool i
   for (uint32_t i = 0; i < gwi.localCols.size(); i++)
     gwi.localCols[i]->sequence(i);
 
-  gwi.select_lex = oldSelectLex;
+  gwi.select_lex = originalSelectLex;
   // append additionalRetCols to returnedCols
   gwi.returnedCols.insert(gwi.returnedCols.begin(), gwi.additionalRetCols.begin(),
                           gwi.additionalRetCols.end());