reset enable_seqscan;

reset enable_indexscan;

reset enable_bitmapscan;

-- This simpler variant of the above test has been observed to fail differently

create table events (event_id int primary key);

create table other_events (event_id int primary key);

create table events_child () inherits (events);

explain (costs off)

select event_id

from (select event_id from events

union all

select event_id from other_events) ss

order by event_id;

QUERY PLAN

----------------------------------------------------------

Merge Append

Sort Key: events.event_id

-> Index Scan using events_pkey on events

-> Sort

Sort Key: events_child.event_id

-> Seq Scan on events_child

-> Index Scan using other_events_pkey on other_events

(7 rows)

drop table events_child, events, other_events;

reset enable_indexonlyscan;

-- Test constraint exclusion of UNION ALL subqueries

explain (costs off)

reset enable_seqscan;

reset enable_indexscan;

reset enable_bitmapscan;

createtableevents (event_idintprimary key);

createtableother_events (event_idintprimary key);

createtableevents_child () inherits (events);

explain (costs off)

select event_id

from (select event_idfrom events

select event_idfrom other_events) ss

order by event_id;

droptable events_child, events, other_events;

reset enable_indexonlyscan;