Hashed file names

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admin
Posts: 8720
Joined: Sun Jan 12, 2003 11:26 pm

Hashed file names

Post by admin »

Hello to all :)
Can anybody give an answer to an philosophical DS question?
Im using DS 4.1 in a solaris environment, and im creating a hashed file
named file1.txt, the job runs and when i go to the O.S. and look for the
file, i only find a file named D_file1.txt not the name ive defined in the
data stage hashed file stage, and i also find a directory named file1.txt
can anybody tel me why?
Thanks
Pedro

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admin
Posts: 8720
Joined: Sun Jan 12, 2003 11:26 pm

Post by admin »

As you can see, hashed files are implemented as O.S. directories!

Regards
Warnke
admin
Posts: 8720
Joined: Sun Jan 12, 2003 11:26 pm

Post by admin »

At 10:33 AM 11/2/01 +0000, you wrote:
>Hello to all :)
>Can anybody give an answer to an philosophical DS question?
>Im using DS 4.1 in a solaris environment, and im creating a hashed file
>named file1.txt, the job runs and when i go to the O.S. and look for the
>file, i only find a file named D_file1.txt not the name ive defined in
>the data stage hashed file stage, and i also find a directory named
>file1.txt can anybody tel me why?


Sure...

In DataStage, we have numerous types of internal files we can create. The
most common for this discussion would be what is known as the hashed file,
or more specifically, what we call the Dynamic Hashed File.

These files are composed of:

D_filename - dictionary/metadata information of the file.
filename - directory containing:
DATA.30 - actual data of file
OVER.30 - overflow data of file

Dave
========================================================================
David T. Meeks || "All my life Im taken by surprise
Development Engineer, DataStage || Im someones waste of time
Ascential Software || Now I walk a balanced line
dave.meeks@ascentialsoftware.com || and step into tomorrow" - IQ
========================================================================
admin
Posts: 8720
Joined: Sun Jan 12, 2003 11:26 pm

Post by admin »

It is not necessarily the case that hashed files are implemented as directories in the operating system.

DYNAMIC hashed files are, but static hashed files (type 2 - 18) are implemented as files in the operating system.

Each hashed file has a file dictionary, which in the operating system is a file named D_hashedfilename.


This information is taught in the "Advanced DataStage" class (not DS305) taught in the Asia-Pacific region.
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