Re: self join revisited - Mailing list pgsql-performance

From Tom Lane
Subject Re: self join revisited
Date
Msg-id 7884.1238606350@sss.pgh.pa.us
Whole thread Raw
In response to self join revisited  (Rikard Pavelic <rikard.pavelic@zg.htnet.hr>)
Responses Re: self join revisited  (Rikard Pavelic <rikard.pavelic@zg.htnet.hr>)
List pgsql-performance
Rikard Pavelic <rikard.pavelic@zg.htnet.hr> writes:
> It would be great if Postgres could rewrite this query

AFAICS those queries are not going to produce the same results,
so Postgres would be 100% incorrect to rewrite it like that for you.

(If they do produce the same results, it would depend on a bunch
of assumptions you have not stated.)

            regards, tom lane

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