Re: Very newbie question - Mailing list pgsql-general

From Олег Самойлов
Subject Re: Very newbie question
Date
Msg-id 50F00665-2AB4-409C-9445-5E32482C0FA4@ya.ru
Whole thread Raw
In response to Very newbie question  (Олег Самойлов <splarv@ya.ru>)
Responses Re: Very newbie question  (Olivier Gautherot <ogautherot@gautherot.net>)
List pgsql-general
Okey, I see no one was be able to solve this problem. But I could. May be for someone this will be useful too. There is
solution.

Original query was:

> 23 окт. 2023 г., в 18:13, Олег Самойлов <splarv@ya.ru> написал(а):
>
> SELECT id/10000000 as partition
>   FROM delivery
>   GROUP BY partition
>   HAVING max(created_at) < CURRENT_DATE - '3 month'::interval;

And I was not able to accelerate it by any index, works 5 minutes. Now query is:

SELECT generate_series(min(id)/10000000, max(id)/10000000) AS n FROM delivery) as part_numbers
         WHERE (SELECT max(created_at) from delivery where n*10000000 <=id and id < (n+1)*10000000)
            < CURRENT_DATE-'3 month'::interval;

Return the same (number of partition need to archive), accelerated by two btree index: on id and created_at. Works very
quick,less then second. 


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