Re: about LEFT and INNER JOIN

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(at)gmail(dot)com]
Enviado el: martes, 30 de mayo de 2017 2:00
Para: Eliober Cleger Despaigne
CC: pgsql-sql(at)postgresql(dot)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(at)uci(dot)cu <mailto:ecleger(at)uci(dot)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