| Author |
Removing data from ISAM file sin bulk |
steg0010
Member
Posts: 2
Joined: 29.11.12 |
| Posted on November 29 2012 01:57 |
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Hi,
What I'm wanting to do is append multiple ISAM files together, but I'm only interested in certain fields. Together the files consist of about 10,000,000 records so I'd prefer it if I didn't have to perform a whole load of IO if possible.
I'd like the output to consist of particular fields from each ISAM, along with the directory the original ISAM came from.
Basically wondering if there's a nice little tool to use to do this quickly that doesn't use too much disk space, as that is fairly limited.
Any Ideas would be great.
Cheers,
Ste |
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| Author |
RE: Removing data from ISAM file sin bulk |
somersdave
Member
Posts: 67
Location: bristol,UK
Joined: 23.03.07 |
| Posted on November 30 2012 08:35 |
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About 10 years since I did anything with ISAM files but I don't think the DCL utility 'APPEND' will be of much use because you want to select certain fields.
Perhaps C or C++ have similar file handling facilities but DEC Fortran was the language of choice (people might disagree) that 'went with' with VMS from the early days - so I'd write a Fortran Program, opening the 'INDEXED' Input files 'READONLY' and the output file with the 'APPEND' attribute, reading the input records and writing out the new data records. (the language user and reference manuals are online and there are probably some example programs)
It would probably wise to make data backups (somewhere) before starting.
Sorry to be a bit vague but I'd need try 'things' to re-familiarize. |
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| Author |
RE: Removing data from ISAM file sin bulk |
steg0010
Member
Posts: 2
Joined: 29.11.12 |
| Posted on December 01 2012 10:11 |
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Hi somersdave,
Thank you for your reply. This project has been moved to somebody else now as I have other more urgent tasks to be getting on with; however, I will inform my colleagues of your advice. If I have any follow up questions I will be sure to return and if we happen to find a solution that I feel would be useful to anybody attempting a similar task I will post it on here.
Thanks again,
Ste |
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| Author |
RE: Removing data from ISAM file sin bulk |
Bruce Claremont
Member
Posts: 623
Joined: 07.01.10 |
| Posted on December 01 2012 17:43 |
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Suggest you hire Hein van den Huevel. He'll write you something clever in Perl. |
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