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Bad plan on a huge table query - Mailing list pgsql-general

From Daniel Cristian Cruz
Subject Bad plan on a huge table query
Date
Msg-id CACffM9H_9fc1OZDyt2Kr4dt8Rvp5+p=2C-839rtTtpMeS5BbUg@mail.gmail.com
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Hi,

I'm trying to figure out why does the planner found 1 row estimate using nested loops over a big table. There is no return from it:


It returns if disable nested loops, but the plan still poor:


I'm using PostgreSQL 9.2.3, default_statistics_target on 1000.

I can't remember what to make PostgreSQL sees a better estimate in the scan of aula_confirmacao and the join with presenca. I got rusty after a long time just doing modeling.

Does someone has some idea on that?

Thanks,
--
Daniel Cristian Cruz
クルズ クリスチアン ダニエル

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