zabbix=# EXPLAIN ANALYZE
SELECT e.*
FROM   events e
WHERE  EXISTS (SELECT NULL
               FROM   functions f,
                      items i,
                      hosts_groups hgg
                      JOIN rights r
                        ON r.id = hgg.groupid
                           AND r.groupid IN ( '32', '50', '56' )
               WHERE  e.objectid = f.triggerid
                      AND f.itemid = i.itemid
                      AND i.hostid = hgg.hostid
               GROUP  BY f.triggerid
               HAVING Min(r.permission) > 0
                      AND Max(r.permission) >= 2)
       AND e.object = '0'
       AND e.source = '0'
ORDER  BY e.clock
LIMIT  1 offset 0;
                                                                               QUERY PLAN

------------------------------------------------------------------------------------------------------------------------------------------------------------------------
-
 Limit  (cost=0.56..61.00 rows=1 width=40) (actual time=146.021..146.021 rows=1 loops=1)
   ->  Index Scan using events_2 on events e  (cost=0.56..76464189.79 rows=1265166 width=40) (actual time=146.020..146.020 rows=1 loops=1)
         Index Cond: ((source = 0) AND (object = 0))
         Filter: (SubPlan 1)
         Rows Removed by Filter: 266
         SubPlan 1
           ->  GroupAggregate  (cost=1.40..29.62 rows=1 width=12) (actual time=0.031..0.031 rows=0 loops=267)
                 Filter: ((min(r.permission) > 0) AND (max(r.permission) >= 2))
                 ->  Nested Loop  (cost=1.40..29.60 rows=1 width=12) (actual time=0.030..0.030 rows=0 loops=267)
                       ->  Nested Loop  (cost=1.13..27.79 rows=5 width=16) (actual time=0.007..0.015 rows=6 loops=267)
                             ->  Nested Loop  (cost=0.85..27.04 rows=2 width=16) (actual time=0.005..0.009 rows=2 loops=267)
                                   ->  Index Scan using functions_1 on functions f  (cost=0.42..10.13 rows=2 width=16) (actual time=0.002..0.003 rows=2 loops=267)
                                         Index Cond: (e.objectid = triggerid)
                                   ->  Index Scan using items_pkey on items i  (cost=0.42..8.45 rows=1 width=16) (actual time=0.002..0.002 rows=1 loops=514)
                                         Index Cond: (itemid = f.itemid)
                             ->  Index Only Scan using hosts_groups_1 on hosts_groups hgg  (cost=0.28..0.34 rows=3 width=16) (actual time=0.001..0.002 rows=3 loops=514)
                                   Index Cond: (hostid = i.hostid)
                                   Heap Fetches: 530
                       ->  Index Scan using rights_2 on rights r  (cost=0.28..0.35 rows=1 width=12) (actual time=0.002..0.002 rows=0 loops=1498)
                             Index Cond: (id = hgg.groupid)
                             Filter: (groupid = ANY ('{32,50,56}'::bigint[]))
                             Rows Removed by Filter: 4
 Total runtime: 146.103 ms
(23 rows)