Re: SET SORT = EXTERNAL
Posted by
Jon K Peck on
URL: http://spssx-discussion.165.s1.nabble.com/SET-SORT-EXTERNAL-tp5714711p5714714.html
The original inspiration for an external
sort had SYNCSORT in mind. That is a product really dedicated specifically
to high performance sorting. Quicksort for nearly sorted data is
not an example, though, where this would apply, since real QS implementations,
including SPSS, deal with the potential bad problems there. But SYNCSORT
plays a lot of other tricks with multiprocessing and other tricks.
So the bottom line is if sorting in
SPSS is taking a really long time, consider SYNCSORT et al.
Jon Peck (no "h") aka Kim
Senior Software Engineer, IBM
[hidden email]
new phone: 720-342-5621
From:
Albert-Jan Roskam <[hidden email]>
To:
[hidden email]
Date:
08/15/2012 03:00 AM
Subject:
[SPSSX-L] SET
SORT = EXTERNAL
Sent by:
"SPSSX(r)
Discussion" <[hidden email]>
Hi,
Has anybody successfully used an external
sorting mechanism? What characteristics should such a mechanism have in
order for spss to be able to use it? When would an external algorithm offer
advantages? (a quicksort for nearly-sorted data?)
SORT Subcommand
By default, IBM® SPSS® Statistics tries to use an external, third-party
sorting mechanism, which
may reduce processing time with large data sources. The third-party sorting
option is available
only if you have SPSS Statistics Server. The specific sorting engine is
defined by your server
administrator. If you are not connected to the SPSS Statistics Server or
the SPSS Statistics Server
cannot find the third-party sort engine, the built-in sorting mechanism
is used.
EXTERNAL Use the external, third-party sort engine if available. This setting
is the default. If
the third-party sort engine is not available, this setting is ignored,
and the built-in
sorting mechanism is used. COXREG and CURVEFIT use built-in sorting regardless
of the SORT setting.
INTERNAL Use the built-in sorting mechanism.
SS This setting is deprecated. It has the same effect as EXTERNAL.
Regards,
Albert-Jan
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