Re: Why order by column not using index with distinct keyword inselect clause?

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От Geoff Winkless
Тема Re: Why order by column not using index with distinct keyword inselect clause?
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Msg-id CAEzk6fdjd7SLk+OvHqTErMwTRs3QvdaUg+T6dY2TrK0zZG6w4A@mail.gmail.com
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Ответ на Why order by column not using index with distinct keyword in selectclause?  (Arup Rakshit <ar@zeit.io>)
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On Tue, 11 Sep 2018 at 13:56, Arup Rakshit <ar@zeit.io> wrote:
I have define a simple B Tree index on column *country* for users table. I don’t understand why the order by column not using the index scan when using *distinct* keyword in the select clause. Can anyone explain what is happening here?

Bear in mind that index skip scans aren't yet implemented, which (unless I've missed the point) seems to be what you're expecting to help here.

https://wiki.postgresql.org/wiki/Loose_indexscan

Geoff

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