Re: about LEFT and INNER JOIN

From: Feike Steenbergen <feikesteenbergen(at)gmail(dot)com>
To: Eliober Cleger Despaigne <ecleger(at)uci(dot)cu>
Cc: pgsql-sql(at)postgresql(dot)org
Subject: Re: about LEFT and INNER JOIN
Date: 2017-05-30 06:00:06
Message-ID: CAK_s-G3iA+2pQYSsH0ckvMTEsSzuFczxRGjFjgWcu29m4OG_5w@mail.gmail.com
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: 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(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
>
>

In response to

Responses

Browse pgsql-sql by date

  From Date Subject
Next Message tel medola 2017-05-30 12:11:53 Re: Lost my tablespace
Previous Message Adrian Klaver 2017-05-29 19:32:20 Re: Lost my tablespace