Re: [HACKERS] sort on huge table - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: [HACKERS] sort on huge table
Date
Msg-id 199911011832.NAA21398@candle.pha.pa.us
Whole thread Raw
In response to Re: [HACKERS] sort on huge table  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: [HACKERS] sort on huge table  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
> Next question is what to do about it.  I don't suppose we have any way
> of turning off the OS' read-ahead algorithm :-(.  We could forget about
> this space-recycling improvement and go back to separate temp files.
> The objection to that, of course, is that while sorting might be faster,
> it doesn't matter how fast the algorithm is if you don't have the disk
> space to execute it.

If I am correct on the Linux seek thing, and Tatsuo is running Linux, is
there any way to fake out the kernel on only Linux, so we issue two
reads in a row before doing a seek?

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