From: hans wulf <lotu1@gmx.net>
To: Maciek Sakrejda <msakrejda@truviso.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: ANTI-JOIN needs table, index scan not possible?
Date: Fri, 11 Mar 2011 18:54:39 +0100
Message-ID: <20110311175439.6380@gmx.net> (raw)
In-Reply-To: <AANLkTink26wyiPdjdd=Tv-me=XFempCnjsJDGj0wbrhJ@mail.gmail.com>
References: <20110311153205.6380@gmx.net>
<AANLkTink26wyiPdjdd=Tv-me=XFempCnjsJDGj0wbrhJ@mail.gmail.com>
Thanks for the answer.
so there's no way around this problem? A nice index bitmap merge thing would be super fast. Big table ANTI JOIN queries with only a few results expected, are totally broken, if this is true.
This way the query breaks my neck. This is a massive downside of postgres which makes this kind of query impossible. Mysql gives you the answer in a few seconds :-(
> Possibly because the index entries you're anti-joining against may
> point to deleted tuples, so you would erroneously omit rows from the
> join result if you skip the visibility check?
>
> ---
> Maciek Sakrejda | System Architect | Truviso
>
> 1065 E. Hillsdale Blvd., Suite 215
> Foster City, CA 94404
> (650) 242-3500 Main
> www.truviso.com
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To: pgsql-performance@postgresql.org
Cc: lotu1@gmx.net, msakrejda@truviso.com
Subject: Re: ANTI-JOIN needs table, index scan not possible?
In-Reply-To: <20110311175439.6380@gmx.net>
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