Re: [HACKERS] One question about transformation ANY Sublinks into joins

2016-07-23 Thread Armor
2, 2016 00:23 AM To: "Armor"<yupengst...@qq.com>; Cc: "pgsql-hackers"<pgsql-hackers@postgresql.org>; Subject: Re: [HACKERS] One question about transformation ANY Sublinks into joins On Sun, Jul 17, 2016 at 5:33 AM, Armor <yupengst...@qq.com> wrote: >

Re: [HACKERS] One question about transformation ANY Sublinks into joins

2016-07-21 Thread Dilip Kumar
On Thu, Jul 21, 2016 at 9:53 PM, Robert Haas wrote: > It would need to be a Hash Semi Join rather than a Hash Join, wouldn't it? I guess, Hash Join will do here, because inner hash node is, on hash aggregate with group key on t2.id2, t2.c2 and hash join condition is

Re: [HACKERS] One question about transformation ANY Sublinks into joins

2016-07-21 Thread Robert Haas
On Sun, Jul 17, 2016 at 5:33 AM, Armor wrote: > Hi > I run a simple SQL with latest PG： > postgres=# explain select * from t1 where id1 in (select id2 from t2 where > c1=c2); > QUERY PLAN >

[HACKERS] One question about transformation ANY Sublinks into joins

2016-07-17 Thread Armor
Hi I run a simple SQL with latest PG?? postgres=# explain select * from t1 where id1 in (select id2 from t2 where c1=c2); QUERY PLAN Seq Scan on t1 (cost=0.00..43291.83 rows=1130