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

From: Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>
To: Claudio Freire <klaussfreire(at)gmail(dot)com>
Cc: Kevin Grittner <kgrittn(at)gmail(dot)com>, Robert Haas <robertmhaas(at)gmail(dot)com>, PostgreSQL-Dev <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: [WIP] [B-Tree] Keep indexes sorted by heap physical location
Date: 2016-08-18 21:23:55
Message-ID: 20160818212355.GA978992@alvherre.pgsql
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

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

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Tom Lane 2016-08-18 21:25:12 Re: distinct estimate of a hard-coded VALUES list
Previous Message Peter Geoghegan 2016-08-18 21:15:41 Re: [WIP] [B-Tree] Keep indexes sorted by heap physical location