Re: Query puts 7.3.4 on endless loop but 7.4beta5 is fine. - Mailing list pgsql-performance

The g in group had to be uppercased, the query produced the same results
but performance was worse  for the IN version .  2367 ms vs 600 ms

rt3=# explain analyze SELECT  * from tickets where id in (  SELECT groups.instance FROM groups
 JOIN principals ON (groups.id = principals.objectid) JOIN cachedgroupmembers ON 
(principals.id = cachedgroupmembers.groupid) JOIN users ON (cachedgroupmembers.memberid = users.id)  
WHERE lower(users.emailaddress) = 'mallah_rajesh@yahoo.com' AND groups.domain = 'RT::Ticket-Role' 
AND groups.type   = 'Requestor' AND principals.principaltype = 'Group' ) AND type = 'ticket' AND 
effectiveid = tickets.id AND (status = 'new' OR status = 'open') ORDER BY priority DESC LIMIT 10;;
                                                                                      QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------Limit  (cost=10078.18..10078.19 rows=1 width=164) (actual time=2367.084..2367.096 rows=4 loops=1)  ->  Sort  (cost=10078.18..10078.19 rows=1 width=164) (actual time=2367.078..2367.082 rows=4 loops=1)        Sort Key: tickets.priority        ->  Hash Join  (cost=10077.65..10078.17 rows=1 width=164) (actual time=2366.870..2367.051 rows=4 loops=1)              Hash Cond: (("outer".instance)::text = ("inner".id)::text)              ->  HashAggregate  (cost=9612.02..9612.02 rows=69 width=8) (actual time=2303.792..2303.810 rows=7 loops=1)                    ->  Hash Join  (cost=4892.97..9611.85 rows=69 width=8) (actual time=1427.260..2303.685 rows=14 loops=1)                          Hash Cond: ("outer".memberid = "inner".id)                          ->  Hash Join  (cost=4523.65..9139.45 rows=13651 width=12) (actual time=948.960..2258.529 rows=31123 loops=1)                                Hash Cond: ("outer".groupid = "inner".id)                                ->  Seq Scan on cachedgroupmembers  (cost=0.00..3456.51 rows=204551 width=8) (actual time=0.048..365.147 rows=204551 loops=1)                                ->  Hash  (cost=4509.93..4509.93 rows=5488 width=12) (actual time=948.843..948.843 rows=0 loops=1)                                      ->  Hash Join  (cost=1409.91..4509.93 rows=5488 width=12) (actual time=315.722..930.025 rows=10431 loops=1)                                            Hash Cond: ("outer".objectid = "inner".id)                                            ->  Seq Scan on principals  (cost=0.00..1583.76 rows=62625 width=8) (actual time=0.043..251.142 rows=62097 loops=1)                                                  Filter: ((principaltype)::text = 'Group'::text)                                            ->  Hash  (cost=1359.90..1359.90 rows=7204 width=12) (actual time=315.458..315.458 rows=0 loops=1)                                                  ->  Index Scan using groups_domain on groups  (cost=0.00..1359.90 rows=7204 width=12) (actual time=0.325..297.403 rows=10431 loops=1)                                                        Index Cond: (("domain")::text = 'RT::Ticket-Role'::text)                                                        Filter: (("type")::text = 'Requestor'::text)                          ->  Hash  (cost=369.08..369.08 rows=101 width=4) (actual time=0.157..0.157 rows=0 loops=1)                                ->  Index Scan using users_emailaddress_lower on users  (cost=0.00..369.08 rows=101 width=4) (actual time=0.139..0.143 rows=1 loops=1)                                      Index Cond: (lower((emailaddress)::text) = 'mallah_rajesh@yahoo.com'::text)              ->  Hash  (cost=465.62..465.62 rows=1 width=164) (actual time=62.944..62.944 rows=0 loops=1)                    ->  Seq Scan on tickets  (cost=0.00..465.62 rows=1 width=164) (actual time=0.113..52.729 rows=3208 loops=1)                          Filter: ((("type")::text = 'ticket'::text) AND (effectiveid = id) AND (((status)::text = 'new'::text) OR ((status)::text = 'open'::text)))Total runtime: 2367.908 ms
(27 rows)



rt3=# explain analyze SELECT DISTINCT main.* FROM ((((Tickets main  JOIN Groups as Groups_1  ON ( main.id = Groups_1.Instance))
rt3(# JOIN Principals as Principals_2  ON ( Groups_1.id = Principals_2.ObjectId)) JOIN CachedGroupMembers as CachedGroupMembers_3
rt3(# ON ( Principals_2.id = CachedGroupMembers_3.GroupId))  JOIN Users as Users_4  ON ( CachedGroupMembers_3.MemberId = Users_4.id))
rt3-# WHERE ((main.EffectiveId = main.id)) AND ((main.Type = 'ticket')) AND ( (  ( (Users_4.EmailAddress = 'mallah_rajesh@yahoo.com')
rt3(# AND(Groups_1.Domain = 'RT::Ticket-Role')AND(Groups_1.Type = 'Requestor')AND(Principals_2.PrincipalType = 'Group') )  )
rt3(# AND ( (main.Status = 'new')OR(main.Status = 'open') ) )  ORDER BY main.Priority DESC LIMIT 10;

                                                                                                                                                                                                      QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------Limit  (cost=582.27..582.34 rows=1 width=164) (actual time=592.406..592.529 rows=4 loops=1)  ->  Unique  (cost=582.27..582.34 rows=1 width=164) (actual time=592.401..592.516 rows=4 loops=1)        ->  Sort  (cost=582.27..582.28 rows=1 width=164) (actual time=592.398..592.406 rows=8 loops=1)              Sort Key: main.priority, main.id, main.effectiveid, main.queue, main."type", main.issuestatement, main.resolution, main."owner", main.subject, main.initialpriority, main.finalpriority, main.timeestimated, main.timeworked, main.status, main.timeleft, main.told, main.starts, main.started, main.due, main.resolved, main.lastupdatedby, main.lastupdated, main.creator, main.created, main.disabled              ->  Hash Join  (cost=476.18..582.26 rows=1 width=164) (actual time=591.548..592.211 rows=8 loops=1)                    Hash Cond: ("outer".groupid = "inner".id)                    ->  Nested Loop  (cost=0.00..105.97 rows=21 width=4) (actual time=0.214..0.645 rows=37 loops=1)                          ->  Index Scan using users4 on users users_4  (cost=0.00..3.99 rows=2 width=4) (actual time=0.107..0.112 rows=1 loops=1)                                Index Cond: ((emailaddress)::text = 'mallah_rajesh@yahoo.com'::text)                          ->  Index Scan using cachedgroupmembers2 on cachedgroupmembers cachedgroupmembers_3  (cost=0.00..50.81 rows=14 width=8) (actual time=0.098..0.441 rows=37 loops=1)                                Index Cond: (cachedgroupmembers_3.memberid = "outer".id)                    ->  Hash  (cost=476.17..476.17 rows=1 width=168) (actual time=591.121..591.121 rows=0 loops=1)                          ->  Nested Loop  (cost=0.00..476.17 rows=1 width=168) (actual time=0.391..583.085 rows=3208 loops=1)                                ->  Nested Loop  (cost=0.00..471.54 rows=1 width=168) (actual time=0.309..474.968 rows=3208 loops=1)                                      ->  Seq Scan on tickets main  (cost=0.00..465.62 rows=1 width=164) (actual time=0.111..56.930 rows=3208 loops=1)                                            Filter: ((effectiveid = id) AND (("type")::text = 'ticket'::text) AND (((status)::text = 'new'::text) OR ((status)::text = 'open'::text)))                                      ->  Index Scan using groups1 on groups groups_1  (cost=0.00..5.90 rows=1 width=12) (actual time=0.105..0.112 rows=1 loops=3208)                                            Index Cond: (((groups_1."domain")::text = 'RT::Ticket-Role'::text) AND (("outer".id)::text = (groups_1.instance)::text) AND ((groups_1."type")::text = 'Requestor'::text))                                ->  Index Scan using principals2 on principals principals_2  (cost=0.00..4.62 rows=1 width=8) (actual time=0.014..0.017 rows=1 loops=3208)                                      Index Cond: ("outer".id = principals_2.objectid)                                      Filter: ((principaltype)::text = 'Group'::text)Total runtime: 593.062 ms
(22 rows)

Regds
Mallah.

Greg Stark wrote:

Rajesh Kumar Mallah <mallah@trade-india.com> writes:
 

Nopes the query are not Equiv , earlier one returns 4 rows and the below one
none,   

Sorry, i lowercased a string constant and dropped the lower() on email. 

Try this:

SELECT * FROM ticketsWHERE id IN (      SELECT groups.instance        FROM groups        JOIN principals ON (groups.id = principals.objectid)        JOIN cachedgroupmembers ON (principals.id = cachedgroupmembers.groupid)        JOIN users ON (cachedgroupmembers.memberid = users.id)       WHERE lower(users.emailaddress) = 'mallah_rajesh@yahoo.com'         AND groups.domain = 'RT::Ticket-Role'         AND groups.type   = 'Requestor'         AND principals.principaltype = 'group' ) AND type = 'ticket' AND effectiveid = tickets.id AND (status = 'new' OR status = 'open')
ORDER BY priority DESC
LIMIT 10;