diff --git a/dbcon/mysql/ha_calpont_execplan.cpp b/dbcon/mysql/ha_calpont_execplan.cpp
index a74b2abdf..88abfb9e1 100644
--- a/dbcon/mysql/ha_calpont_execplan.cpp
+++ b/dbcon/mysql/ha_calpont_execplan.cpp
@@ -7779,8 +7779,9 @@ int getSelectPlan(gp_walk_info& gwi, SELECT_LEX& select_lex,
                hash join, giving less number of rows in the output result set than expected.
                We therefore do not allow limit set to 1 here for such queries.
             */
-            if (gwi.subSelectType != CalpontSelectExecutionPlan::IN_SUBS &&
-                select_lex.master_unit()->global_parameters()->explicit_limit)
+            if (gwi.subSelectType != CalpontSelectExecutionPlan::IN_SUBS
+                 && gwi.subSelectType != CalpontSelectExecutionPlan::EXISTS_SUBS
+                 && select_lex.master_unit()->global_parameters()->explicit_limit)
             {
                 if (select_lex.master_unit()->global_parameters()->offset_limit)
                 {
diff --git a/dbcon/mysql/ha_calpont_impl.cpp b/dbcon/mysql/ha_calpont_impl.cpp
index c39cef8a0..67a524eef 100644
--- a/dbcon/mysql/ha_calpont_impl.cpp
+++ b/dbcon/mysql/ha_calpont_impl.cpp
@@ -2747,12 +2747,6 @@ int ha_calpont_impl_rnd_end(TABLE* table, bool is_pushdown_hand)
             ((thd->lex)->sql_command == SQLCOM_UPDATE_MULTI))
         return rc;
 
-    if (((thd->lex)->sql_command == SQLCOM_INSERT) ||
-            ((thd->lex)->sql_command == SQLCOM_INSERT_SELECT) )
-    {
-       force_close_fep_conn(thd, ci, true); // checking prev command rc
-    }
-
     if (!ci)
     {
         set_fe_conn_info_ptr((void*)new cal_connection_info());
@@ -4042,7 +4036,11 @@ int ha_calpont_impl_external_lock(THD* thd, TABLE* table, int lock_type)
 
 
     CalTableMap::iterator mapiter = ci->tableMap.find(table);
-    if (mapiter != ci->tableMap.end() && lock_type == 2) // make sure it's the release lock (2nd) call
+    // make sure this is a release lock (2nd) call called in
+    // the table mode.
+    if (mapiter != ci->tableMap.end()
+          && (mapiter->second.condInfo && mapiter->second.csep)
+          && lock_type == 2)
     {
         // table mode
         if (mapiter->second.conn_hndl)
@@ -4068,14 +4066,18 @@ int ha_calpont_impl_external_lock(THD* thd, TABLE* table, int lock_type)
         // Clean up the tableMap and physTablesList
         ci->tableMap.erase(table);
         ci->physTablesList.erase(table);
+        thd->variables.in_subquery_conversion_threshold = IN_SUBQUERY_CONVERSION_THRESHOLD;
+        restore_optimizer_flags(thd);
     }
     else
     {
-        if (lock_type == 0) 
+        if (lock_type == 0)
         {
             ci->physTablesList.insert(table);
             // MCOL-2178 Disable Conversion of Big IN Predicates Into Subqueries
-            thd->variables.in_subquery_conversion_threshold=~0;
+            thd->variables.in_subquery_conversion_threshold=~ 0;
+            // Early optimizer_switch changes to avoid unsupported opt-s.
+            mutate_optimizer_flags(thd);
         }
         else if (lock_type == 2)
         {
@@ -4100,6 +4102,15 @@ int ha_calpont_impl_external_lock(THD* thd, TABLE* table, int lock_type)
                 // MCOL-3247 Use THD::ha_data as a per-plugin per-session
                 // storage for cal_conn_hndl to use it later in close_connection
                 thd_set_ha_data(thd, mcs_hton, get_fe_conn_info_ptr());
+                // Clean up all tableMap entries made by cond_push
+                for (auto &tme: ci->tableMap)
+                {
+                    if (tme.second.condInfo)
+                    {
+                        delete tme.second.condInfo;
+                        tme.second.condInfo= 0;
+                    }
+                }
                 ci->tableMap.clear();
                 // MCOL-2178 Enable Conversion of Big IN Predicates Into Subqueries
                 thd->variables.in_subquery_conversion_threshold = IN_SUBQUERY_CONVERSION_THRESHOLD;
diff --git a/dbcon/mysql/ha_exists_sub.cpp b/dbcon/mysql/ha_exists_sub.cpp
index ee3326803..9db9294c9 100644
--- a/dbcon/mysql/ha_exists_sub.cpp
+++ b/dbcon/mysql/ha_exists_sub.cpp
@@ -112,7 +112,7 @@ execplan::ParseTree* ExistsSub::transform()
         return NULL;
     }
 
-    if (getSelectPlan(gwi, *(fSub->get_select_lex()), csep) != 0)
+    if (getSelectPlan(gwi, *(fSub->get_select_lex()), csep, false, true) != 0)
     {
         fGwip.fatalParseError = true;
 
diff --git a/dbcon/mysql/ha_in_sub.cpp b/dbcon/mysql/ha_in_sub.cpp
index a582ea5bf..4d1e828ce 100644
--- a/dbcon/mysql/ha_in_sub.cpp
+++ b/dbcon/mysql/ha_in_sub.cpp
@@ -148,7 +148,7 @@ execplan::ParseTree* InSub::transform()
     gwi.tbList.insert(gwi.tbList.begin(), fGwip.tbList.begin(), fGwip.tbList.end());
     gwi.derivedTbList.insert(gwi.derivedTbList.begin(), fGwip.derivedTbList.begin(), fGwip.derivedTbList.end());
 
-    if (getSelectPlan(gwi, *(fSub->get_select_lex()), csep) != 0)
+    if (getSelectPlan(gwi, *(fSub->get_select_lex()), csep, false, true) != 0)
     {
         fGwip.fatalParseError = true;
 
diff --git a/dbcon/mysql/ha_mcs_pushdown.cpp b/dbcon/mysql/ha_mcs_pushdown.cpp
index 3caca6189..3f034d412 100644
--- a/dbcon/mysql/ha_mcs_pushdown.cpp
+++ b/dbcon/mysql/ha_mcs_pushdown.cpp
@@ -286,8 +286,8 @@ void check_user_var_func(const Item* item, void* arg)
     if (item->type() == Item::FUNC_ITEM)
     {
         const Item_func* ifp = reinterpret_cast<const Item_func*>(item);
-        std::string funcName = ifp->func_name();
-        if (funcName == "set_user_var" || funcName == "get_user_var")
+        std::string funcname = ifp->func_name();
+        if (funcname == "set_user_var" || funcname == "get_user_var")
         {
             *unsupported_feature = true;
         }
@@ -455,16 +455,8 @@ create_columnstore_derived_handler(THD* thd, TABLE_LIST *derived)
     SELECT_LEX *sl= unit->first_select();
 
     bool unsupported_feature = false;
-    // Select_handler use the short-cut that effectively disables
-    // INSERT..SELECT and LDI
-    if ( (thd->lex)->sql_command == SQLCOM_INSERT_SELECT
-        || (thd->lex)->sql_command == SQLCOM_CREATE_TABLE)
-    {
-        unsupported_feature = true;
-    }
 
     // Impossible HAVING or WHERE
-    // TODO replace with function call
     if ( unsupported_feature
        || sl->having_value == Item::COND_FALSE
         || sl->cond_value == Item::COND_FALSE )
@@ -517,6 +509,14 @@ create_columnstore_derived_handler(THD* thd, TABLE_LIST *derived)
         }
     }
 
+    if (!unsupported_feature && !join_preds_list.elements
+          && join && join->conds)
+    {
+        Item_cond* conds= reinterpret_cast<Item_cond*>(join->conds);
+        conds->traverse_cond(check_walk, &unsupported_feature, Item::POSTFIX);
+        conds->traverse_cond(save_join_predicates, &join_preds_list, Item::POSTFIX);
+    }
+
     // CROSS JOIN w/o conditions isn't supported until MCOL-301
     // is ready.
     if (!unsupported_feature && join
@@ -718,15 +718,17 @@ create_columnstore_select_handler(THD* thd, SELECT_LEX* select_lex)
         return handler;
     }
 
+    // This block gives false positive in
+    // partitionOptimization/vTpch11.
     // Disable SH processing for UNION in a subquery.
     // This way, the server falls back to using the DH for executing
     // the UNION, if enabled.
-    TABLE_LIST *tbl_ptr = select_lex->get_table_list();
+    /*TABLE_LIST *tbl_ptr = select_lex->get_table_list();
     if (tbl_ptr && tbl_ptr->derived &&
         (tbl_ptr->derived->is_unit_op() || tbl_ptr->derived->fake_select_lex))
     {
         return handler;
-    }
+    }*/
 
     bool unsupported_feature = false;
     // Select_handler use the short-cut that effectively disables
@@ -744,8 +746,7 @@ create_columnstore_select_handler(THD* thd, SELECT_LEX* select_lex)
     // if execution fails.
     if (!unsupported_feature)
     {
-        // TODO This part must explicitly call a list of needed optimizations
-        mutate_optimizer_flags(thd);
+        // Most of optimizer_switch flags disabled in external_lock
         join->optimization_state= JOIN::OPTIMIZATION_IN_PROGRESS;
         join->optimize_inner();
 
diff --git a/dbcon/mysql/ha_scalar_sub.cpp b/dbcon/mysql/ha_scalar_sub.cpp
index debd777f0..f41482ba2 100644
--- a/dbcon/mysql/ha_scalar_sub.cpp
+++ b/dbcon/mysql/ha_scalar_sub.cpp
@@ -253,7 +253,7 @@ execplan::ParseTree* ScalarSub::buildParseTree(PredicateOperator* op)
     gwi.tbList.insert(gwi.tbList.begin(), fGwip.tbList.begin(), fGwip.tbList.end());
     gwi.derivedTbList.insert(gwi.derivedTbList.begin(), fGwip.derivedTbList.begin(), fGwip.derivedTbList.end());
 
-    if (getSelectPlan(gwi, *(fSub->get_select_lex()), csep) != 0)
+    if (getSelectPlan(gwi, *(fSub->get_select_lex()), csep, false, true) != 0)
     {
         //@todo more in error handling
         if (!gwi.fatalParseError)
diff --git a/dbcon/mysql/ha_select_sub.cpp b/dbcon/mysql/ha_select_sub.cpp
index 0b003b664..708d2cca8 100644
--- a/dbcon/mysql/ha_select_sub.cpp
+++ b/dbcon/mysql/ha_select_sub.cpp
@@ -77,7 +77,7 @@ SCSEP SelectSubQuery::transform()
     gwi.tbList.insert(gwi.tbList.begin(), fGwip.tbList.begin(), fGwip.tbList.end());
     gwi.derivedTbList.insert(gwi.derivedTbList.begin(), fGwip.derivedTbList.begin(), fGwip.derivedTbList.end());
 
-    if (getSelectPlan(gwi, *(fSelSub->get_select_lex()), csep) != 0)
+    if (getSelectPlan(gwi, *(fSelSub->get_select_lex()), csep, false, true) != 0)
     {
         if (!gwi.fatalParseError)
         {