Hello
I execute following query to the partitioned table, but the plan is different
from my assumption, so please tell me the reason.
postgres=# explain select * from jta, (select a, max(b) from jtb where a = 1
group by a ) c1 where jta.a = c1.a;
QUERY PLAN
Hello
I execute following query to the partitioned table, but the plan is different
from my assumption, so please tell me the reason.
postgres=# explain select * from jta, (select a, max(b) from jtb where a = 1
group by a ) c1 where jta.a = c1.a;
QUERY PLAN
On Fri, 24 May 2019 at 19:44, Kato, Sho wrote:
> I execute following query to the partitioned table, but the plan is different
> from my assumption, so please tell me the reason.
>
> postgres=# explain select * from jta, (select a, max(b) from jtb where a = 1
> group by a ) c1 where jta.a = c1.
> From: David Rowley [mailto:david.row...@2ndquadrant.com]
> Sent: Friday, May 24, 2019 5:10 PM
> To: Kato, Sho/加藤 翔
> Cc: pgsql-hack...@postgresql.org
> Subject: Re: Why does not subquery pruning conditions inherit to parent
> query?
>
> On Fri, 24 May 2019 at 19:44, Kat
"Kato, Sho" writes:
> Friday, May 24, 2019 5:10 PM, David Rowley wrote:
>> The planner can only push quals down into a subquery, it cannot pull quals
>> from a subquery into the outer query.
> However, following query looks like the subquery qual is pushed down into the
> outer query.
> postgres
> Sent: Monday, May 27, 2019 7:56 PM
> To: Kato, Sho/加藤 翔
> Cc: 'David Rowley' ;
> pgsql-hack...@postgresql.org
> Subject: Re: Why does not subquery pruning conditions inherit to parent
> query?
>
> "Kato, Sho" writes:
> > Friday, May 24, 2019 5:10
On Fri, 31 May 2019 at 03:18, Kato, Sho wrote:
> Is it possible to improve a subquery quals to pull up into outer query?
Sure, it's possible, but it would require writing code. When it can
and cannot/should not be done would need to be determined.
--
David Rowley http://www.2
partition pruning
does not work on the wiki.
Thoughts?
Regards,
kato sho
> -Original Message-
> From: David Rowley [mailto:david.row...@2ndquadrant.com]
> Sent: Friday, May 31, 2019 9:33 PM
> To: Kato, Sho/加藤 翔
> Cc: Tom Lane ; pgsql-hack...@postgresql.org
> Subject: Re:
On Thu, 6 Jun 2019 at 19:47, Kato, Sho wrote:
>
> On Friday, May 31, 2019 9:33 PM, David Rowley wrote:
> > Sure, it's possible, but it would require writing code. When it can and
> > cannot/should not be done would need to be determined.
>
> Is there any harmful effect by pulling up a subquery qua
On Fri, 24 May 2019 at 19:44, Kato, Sho wrote:
> I execute following query to the partitioned table, but the plan is different
> from my assumption, so please tell me the reason.
>
> postgres=# explain select * from jta, (select a, max(b) from jtb where a = 1
> group by a ) c1 where jta.a = c1.
> From: David Rowley [mailto:david.row...@2ndquadrant.com]
> Sent: Friday, May 24, 2019 5:10 PM
> To: Kato, Sho/加藤 翔
> Cc: pgsql-hack...@postgresql.org
> Subject: Re: Why does not subquery pruning conditions inherit to parent
> query?
>
> On Fri, 24 May 2019 at 19:44, Kat
"Kato, Sho" writes:
> Friday, May 24, 2019 5:10 PM, David Rowley wrote:
>> The planner can only push quals down into a subquery, it cannot pull quals
>> from a subquery into the outer query.
> However, following query looks like the subquery qual is pushed down into the
> outer query.
> postgres
> Sent: Monday, May 27, 2019 7:56 PM
> To: Kato, Sho/加藤 翔
> Cc: 'David Rowley' ;
> pgsql-hack...@postgresql.org
> Subject: Re: Why does not subquery pruning conditions inherit to parent
> query?
>
> "Kato, Sho" writes:
> > Friday, May 24, 2019 5:10
On Fri, 31 May 2019 at 03:18, Kato, Sho wrote:
> Is it possible to improve a subquery quals to pull up into outer query?
Sure, it's possible, but it would require writing code. When it can
and cannot/should not be done would need to be determined.
--
David Rowley http://www.2
partition pruning
does not work on the wiki.
Thoughts?
Regards,
kato sho
> -Original Message-
> From: David Rowley [mailto:david.row...@2ndquadrant.com]
> Sent: Friday, May 31, 2019 9:33 PM
> To: Kato, Sho/加藤 翔
> Cc: Tom Lane ; pgsql-hack...@postgresql.org
> Subject: Re:
On Thu, 6 Jun 2019 at 19:47, Kato, Sho wrote:
>
> On Friday, May 31, 2019 9:33 PM, David Rowley wrote:
> > Sure, it's possible, but it would require writing code. When it can and
> > cannot/should not be done would need to be determined.
>
> Is there any harmful effect by pulling up a subquery qua
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