Combine fields filter in exposed form not workinig with ORACLE

I had a view and an exposed search form. All other search filters are all working fine except Combine fields filter (Title + short description) and date range.

Error in views preview for Combine fields filter (Title + short description)

SELECT COUNT() AS expression FROM (SELECT 1 AS expression FROM {node} node LEFT JOIN {field_data_field_short_description_event} field_data_field_short_description_event ON node.nid = field_data_field_short_description_event.entity_id AND (field_data_field_short_description_event.entity_type = :views_join_condition_2 AND field_data_field_short_description_event.deleted = :views_join_condition_3) WHERE (( (node.status = :db_condition_placeholder_0) AND (node.type IN (:db_condition_placeholder_1)) AND (CONCAT_WS(' ', node.title, ' ', field_data_field_short_description_event.field_short_description_event_value) LIKE :views_combine) ))) subquery (prepared: SELECT COUNT() AS expression FROM (SELECT 1 AS expression FROM "NODE" node LEFT JOIN "L#779" L#779 ON node.nid = L#779.entity_id AND (L#779.entity_type = :views_join_condition_2 AND L#779.deleted = :views_join_condition_3) WHERE (( (node.status = :db_condition_placeholder_0) AND (node.type IN (:db_condition_placeholder_1)) AND (CONCAT_WS(' ', node.title, ' ', L#779.L#780) LIKE :views_combine) ))) subquery ) e: SQLSTATE[HY000]: General error: 904 OCIStmtExecute: ORA-00904: "CONCAT_WS": invalid identifier (/tmp/pear/download/PDO_OCI-1.0/oci_statement.c:142) args: Array ( [:db_condition_placeholder_0] => 1 [:db_condition_placeholder_1] => event [:views_combine] => %Testing% [:views_join_condition_2] => node [:views_join_condition_3] => 0 )

Error in views preview for date range (Start date & end date)

SELECT COUNT() AS expression FROM (SELECT 1 AS expression FROM {node} node LEFT JOIN {field_data_field_end_date_event} field_data_field_end_date_event ON node.nid = field_data_field_end_date_event.entity_id AND (field_data_field_end_date_event.entity_type = :views_join_condition_4 AND field_data_field_end_date_event.deleted = :views_join_condition_5) LEFT JOIN {field_data_field_start_date_event} field_data_field_start_date_event ON node.nid = field_data_field_start_date_event.entity_id AND (field_data_field_start_date_event.entity_type = :views_join_condition_6 AND field_data_field_start_date_event.deleted = :views_join_condition_7) WHERE (( (node.status = :db_condition_placeholder_0) AND (node.type IN (:db_condition_placeholder_1)) AND ( >= :node_date_filter AND <= :node_date_filter1 AND >= :node_date_filter2 AND <= :node_date_filter3) ))) subquery (prepared: SELECT COUNT() AS expression FROM (SELECT 1 AS expression FROM "NODE" node LEFT JOIN "L#842" L#842 ON node.nid = L#842.entity_id AND (L#842.entity_type = :views_join_condition_4 AND L#842.deleted = :views_join_condition_5) LEFT JOIN "L#822" L#822 ON node.nid = L#822.entity_id AND (L#822.entity_type = :views_join_condition_6 AND L#822.deleted = :views_join_condition_7) WHERE (( (node.status = :db_condition_placeholder_0) AND (node.type IN (:db_condition_placeholder_1)) AND ( >= :node_date_filter AND <= :node_date_filter1 AND >= :node_date_filter2 AND <= :node_date_filter3) ))) subquery ) e: SQLSTATE[HY000]: General error: 936 OCIStmtExecute: ORA-00936: missing expression (/tmp/pear/download/PDO_OCI-1.0/oci_statement.c:142) args: Array ( [:db_condition_placeholder_0] => 1 [:db_condition_placeholder_1] => event [:node_date_filter] => 2015-01-01 [:node_date_filter1] => 2015-01-05 [:node_date_filter2] => 2015-01-01 [:node_date_filter3] => 2015-01-05 [:views_join_condition_4] => node [:views_join_condition_5] => 0 [:views_join_condition_6] => node [:views_join_condition_7] => 0 )