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Re: [SQL] about LEFT and INNER JOIN - Mailing list pgsql-sql

From Feike Steenbergen
Subject Re: [SQL] about LEFT and INNER JOIN
Date
Msg-id CAK_s-G3iA+2pQYSsH0ckvMTEsSzuFczxRGjFjgWcu29m4OG_5w@mail.gmail.com
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In response to [SQL] about LEFT and INNER JOIN  ("Eliober Cleger Despaigne" <ecleger@uci.cu>)
Responses Re: [SQL] about LEFT and INNER JOIN
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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


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