Re: [HACKERS] sort on huge table

From: Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us>
To: "Aaron J(dot) Seigo" <aaron(at)gtv(dot)ca>
Cc: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, t-ishii(at)sra(dot)co(dot)jp, pgsql-hackers(at)postgreSQL(dot)org
Subject: Re: [HACKERS] sort on huge table
Date: 1999-11-01 19:13:46
Message-ID: 199911011913.OAA27394@candle.pha.pa.us
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> hi...
>
> > Look what I found. I downloaded Linux kernel source for 2.2.0, and
> > started looking for the word 'ahead' in the file system files. I found
> > that read-ahead seems to be controlled by f_reada, and look where I
> > found it being turned off? Seems like any seek turns off read-ahead on
> > Linux.
>
> the current kernel is 2.2.13... =)

I need to know what kernel the tester is using. I doubt it is the most
current one.

> that said, the fs/ext2/file.c is the same in 2.2.13 as it is in 2.2.0 (just
> checked).. i'm going to put this out on the linux kernel mailing list and see
> what comes back, though, as this seems to be an issue that should be
> resolved if accurate....

I am not sure I am accurate either, but I think I am.

It would be nice to get the kernel fixed, though a fix for that is
rarely trivial.

Let us know what your find out.

--
Bruce Momjian | http://www.op.net/~candle
maillist(at)candle(dot)pha(dot)pa(dot)us | (610) 853-3000
+ If your life is a hard drive, | 830 Blythe Avenue
+ Christ can be your backup. | Drexel Hill, Pennsylvania 19026

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