postgres=# explain  SELECT l.id
                        FROM hdb_catalog.event_log l
                        JOIN hdb_catalog.event_triggers e
                        ON (l.trigger_name = e.name)
                        WHERE l.delivered ='f' and l.error = 'f' and l.locked = 'f'
                              and (l.next_retry_at is NULL or l.next_retry_at <= now())
                        FOR UPDATE SKIP LOCKED
                        LIMIT 100 ;
                                                                QUERY PLAN                                                                
------------------------------------------------------------------------------------------------------------------------------------------
 Limit  (cost=0.57..30.06 rows=100 width=49)
   ->  LockRows  (cost=0.57..64027.16 rows=217110 width=49)
         ->  Merge Join  (cost=0.57..61856.06 rows=217110 width=49)
               Merge Cond: (l.trigger_name = e.name)
               ->  Index Scan using event_log_trigger_name_idx on event_log l  (cost=0.42..59087.56 rows=217110 width=56)
                     Filter: ((NOT delivered) AND (NOT error) AND (NOT locked) AND ((next_retry_at IS NULL) OR (next_retry_at <= now())))
               ->  Index Scan using event_triggers_pkey on event_triggers e  (cost=0.15..53.70 rows=370 width=38)
(7 rows)

postgres=# explain  SELECT l.id
                        FROM (select id, trigger_name from hdb_catalog.event_log 
                                      WHERE delivered ='f' and error = 'f' and locked = 'f'
                              and (next_retry_at is NULL or next_retry_at <= now()) and archived = 'f') l
                        FOR UPDATE SKIP LOCKED
                        LIMIT 100;
                                                                      QUERY PLAN                                                                       
-------------------------------------------------------------------------------------------------------------------------------------------------------
 Limit  (cost=0.42..16.54 rows=100 width=43)
   ->  LockRows  (cost=0.42..34995.02 rows=217110 width=43)
         ->  Index Scan using event_log_delivered_idx on event_log  (cost=0.42..32823.92 rows=217110 width=43)
               Index Cond: (delivered = false)
               Filter: ((NOT delivered) AND (NOT error) AND (NOT locked) AND (NOT archived) AND ((next_retry_at IS NULL) OR (next_retry_at <= now())))
(5 rows)