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* about LEFT and INNER JOIN
@ 2017-05-23 18:38 Eliober Cleger Despaigne <ecleger@uci.cu>
2017-05-30 06:00 ` Re: about LEFT and INNER JOIN Feike Steenbergen <feikesteenbergen@gmail.com>
0 siblings, 1 reply; 3+ messages in thread
From: Eliober Cleger Despaigne @ 2017-05-23 18:38 UTC (permalink / raw)
To: pgsql-sql
Grettings
I need to know which algorithm uses the INNER JOIN and LEFT JOIN. If would
be possible, I need to know their costs too in O(n) notation.
La @universidad_uci es Fidel. Los jóvenes no fallaremos.
#HastaSiempreComandante
#HastalaVictoriaSiempre
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: about LEFT and INNER JOIN
2017-05-23 18:38 about LEFT and INNER JOIN Eliober Cleger Despaigne <ecleger@uci.cu>
@ 2017-05-30 06:00 ` Feike Steenbergen <feikesteenbergen@gmail.com>
2017-05-30 12:20 ` Re: about LEFT and INNER JOIN Eliober Cleger Despaigne <ecleger@uci.cu>
0 siblings, 1 reply; 3+ messages in thread
From: Feike Steenbergen @ 2017-05-30 06:00 UTC (permalink / raw)
To: Eliober Cleger Despaigne <ecleger@uci.cu>; +Cc: pgsql-sql
The join strategies PostgreSQL can use are outlined here:
https://www.postgresql.org/docs/current/static/planner-optimizer.html
basically either a:
- nested loop join O(n*m)
- merge join O(n+m)
- hash join O(n+m)
regards,
Feike
On 23 May 2017 at 20:38, Eliober Cleger Despaigne <ecleger@uci.cu> wrote:
> Grettings
>
> I need to know which algorithm uses the INNER JOIN and LEFT JOIN. If would
> be possible, I need to know their costs too in O(n) notation.
>
> ------------------------------
> La @universidad_uci es Fidel. Los jóvenes no fallaremos.
> #HastaSiempreComandante #HastalaVictoriaSiempre
>
>
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: about LEFT and INNER JOIN
2017-05-23 18:38 about LEFT and INNER JOIN Eliober Cleger Despaigne <ecleger@uci.cu>
2017-05-30 06:00 ` Re: about LEFT and INNER JOIN Feike Steenbergen <feikesteenbergen@gmail.com>
@ 2017-05-30 12:20 ` Eliober Cleger Despaigne <ecleger@uci.cu>
0 siblings, 0 replies; 3+ messages in thread
From: Eliober Cleger Despaigne @ 2017-05-30 12:20 UTC (permalink / raw)
To: 'Feike Steenbergen' <feikesteenbergen@gmail.com>; +Cc: pgsql-sql
Sorry, I forgot specify the PostgreSQL version which is 9.4
Ing. Eliober Cleger Despaigne
Vicedecano de Extensión y Residencia, Facultad 3
Telf: 8040
De: Feike Steenbergen [mailto:feikesteenbergen@gmail.com]
Enviado el: martes, 30 de mayo de 2017 2:00
Para: Eliober Cleger Despaigne
CC: pgsql-sql@postgresql.org
Asunto: Re: [SQL] about LEFT and INNER JOIN
The join strategies PostgreSQL can use are outlined here:
https://www.postgresql.org/docs/current/static/planner-optimizer.html
basically either a:
- nested loop join O(n*m)
- merge join O(n+m)
- hash join O(n+m)
regards,
Feike
On 23 May 2017 at 20:38, Eliober Cleger Despaigne <ecleger@uci.cu <mailto:ecleger@uci.cu> > wrote:
Grettings
I need to know which algorithm uses the INNER JOIN and LEFT JOIN. If would be possible, I need to know their costs too in O(n) notation.
_____
La @universidad_uci es Fidel. Los jóvenes no fallaremos. #HastaSiempreComandante #HastalaVictoriaSiempre
La @universidad_uci es Fidel. Los jóvenes no fallaremos.
#HastaSiempreComandante
#HastalaVictoriaSiempre
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2017-05-23 18:38 about LEFT and INNER JOIN Eliober Cleger Despaigne <ecleger@uci.cu>
2017-05-30 06:00 ` Feike Steenbergen <feikesteenbergen@gmail.com>
2017-05-30 12:20 ` Eliober Cleger Despaigne <ecleger@uci.cu>
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