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From:Fred Lindberg Date:March 11 1999 9:28pm
Subject:Re: Splitting query results among machines?
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On Thu, 11 Mar 1999 13:21:15 -0800 (PST), Brian Bray wrote:

>My question is how do I run a query and then reliably split the results of
>the query among multiple machines.  Say for example I do a SELECT * FROM
>Bookmarks.  I want machine 1 to handle the first 1/3 of the
>resulting rows, machine 2 the 2nd 1/3 and so on.
>
>Any good Idea's?

For ezmlm, a 53 way hash is calculated and stored with each address.
The load can then be split. You can to your data add a column with
either a hash or a random number (depending on if the number has to be
calculatable from the data), then into your select add e.g. WHERE hash
BETWEEN 0 AND 17, etc. As long as you cover the entire range without
overlap, you can split any way you want.


-Sincerely, Fred

(Frederik Lindberg, Infectious Diseases, WashU, St. Louis, MO, USA)


Thread
sort of defragmentation?Mike Otto11 Mar
  • Re: sort of defragmentation?kalle volkov11 Mar
  • Re: sort of defragmentation?Christian Mack11 Mar
    • Re: sort of defragmentation?Charles Kirby11 Mar
      • Re: sort of defragmentation?Sasha Pachev11 Mar
        • Re: sort of defragmentation?Charles Kirby11 Mar
          • Re: sort of defragmentation?Sasha Pachev11 Mar
            • Re: sort of defragmentation?Charles Kirby11 Mar
              • Splitting query results among machines?Brian Bray11 Mar
                • RE: Splitting query results among machines?Brett Error11 Mar
  • SIGSEV using Mysql++Sander Pilon26 Aug
Re: sort of defragmentation?Ed Carp11 Mar
  • Re: sort of defragmentation?Sasha Pachev11 Mar
Re: sort of defragmentation?Ed Carp11 Mar
  • Re: sort of defragmentation?Christian Mack12 Mar
Re: Splitting query results among machines?Fred Lindberg11 Mar
Re: sort of defragmentation?Ed Carp12 Mar
Re: sort of defragmentation?Christian Mack13 Mar
Re: sort of defragmentation?Ed Carp13 Mar