Re: [WIP] [B-Tree] Keep indexes sorted by heap physical location

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От Alvaro Herrera
Тема Re: [WIP] [B-Tree] Keep indexes sorted by heap physical location
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Msg-id 20160818212355.GA978992@alvherre.pgsql
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Ответ на Re: [WIP] [B-Tree] Keep indexes sorted by heap physical location  (Claudio Freire <klaussfreire@gmail.com>)
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Claudio Freire wrote:

> Unique indexes still need to scan all duplicates to check visibility
> and will become O(N^2) there.

That scenario doesn't matter, because on unique indexes there aren't
many duplicate values anyway -- only one can be a live tuple.

-- 
Álvaro Herrera                http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

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