I should have mentioned that the data is UTF-8 not strictly ASCII and we
need to preserve the encoding.

I could probably do this without it being "inplace" let's consider that a
"nice to have".


On Thu, Jan 2, 2014 at 10:17 AM, Lloyd Brown <[email protected]> wrote:

> I'm not aware of anything that will do in-place merges, but have you
> considered compressing them first, to save enough space, that you could
> manage it without being in-place?  I've seen ASCII compress at 6:1 or
> more, but it will depend on the specific data.
>
> Basically something roughly like this (verify the syntax first):
>
> > #compress individual files
> > for i in file1 file2; do gzip --verbose $i; done
> > #merge them to a new file
> > zcat file1.gz file2.gz | sort -u | gzip > file3.gz
>
> Not sure if that will save you enough space to get it done without being
> in-place or not.  But worth considering.
>
> Lloyd Brown
> Systems Administrator
> Fulton Supercomputing Lab
> Brigham Young University
> http://marylou.byu.edu
>
> On 01/02/2014 10:12 AM, S. Dale Morrey wrote:
> > I have a 15 GB file and a 2 GB file.  Both are sourced from somewhat
> > similar data so there could be quite a lot of overlap, both are in the
> same
> > format, i.e. plaintext CSV 1 entry per line.
> >
> > I'd like to read the 2GB file and add any entries that are present in it,
> > but missing in the 15GB file, basically merging the 2 files.  Space is
> at a
> > premium so I'd prefer it be an in place merge onto the 15GB file.  Even
> if
> > a temp file is made, It would still be best if the end result was a
> single
> > 17GB file.
> >
> > I don't want to reinvent the wheel.  The time to perform the operation is
> > irrelevant, but I'd greatly prefer there not be any dupes.  Is there a
> bash
> > command that could facilitate the activity?
> >
> > /*
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> >
>
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