Subject: Re: [PERFORM] A Better External Sort?
From: Simon Riggs <simon@2ndquadrant.com>
To: Martijn van Oosterhout <kleptog@svana.org>
Cc: Tom Lane <tgl@sss.pgh.pa.us>,
	Ron Peacetree <rjpeace@earthlink.net>, pgsql-hackers@postgresql.org
In-Reply-To: <20051002193835.GJ30492@svana.org>
References: 
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	<20051002123240.GA30492@svana.org> <20051002193835.GJ30492@svana.org>
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Organization: 2nd Quadrant
Date: Mon, 03 Oct 2005 22:51:32 +0100
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On Sun, 2005-10-02 at 21:38 +0200, Martijn van Oosterhout wrote:
> Ok, I tried two optimisations:
> 

> 2. By specifying: -Winline -finline-limit-1500 (only on tuplesort.c).
> This causes inlineApplySortFunction() to be inlined, like the code
> obviously expects it to be.
> 
> default build (baseline)                    235 seconds
> -finline only                               217 seconds (7% better)
> comparetup_index_fastbyval4 only            221 seconds (6% better)
> comparetup_index_fastbyval4 and -finline    203 seconds (13.5% better)
> 
> This is indexing the integer sequence column on a 2.7 million row
> table. The times are as given by gprof and so exclude system call time.
> 
> Basically, I recommend adding "-Winline -finline-limit-1500" to the
> default build while we discuss other options.

I add -Winline but get no warnings. Why would I use -finline-limit-1500?

I'm interested, but uncertain as to what difference this makes. Surely
using -O3 works fine?

Best Regards, Simon Riggs