Author Topic: Compression - Which File Types Should be Compressed?  (Read 2740 times)

BHUMENY

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Compression - Which File Types Should be Compressed?
« on: March 23, 2017, 08:17:29 AM »
We have documents of the following types that we are migrating from CM for i to OnDemand for i:
PDF
XLS
XML
HTML
XLSX
MSG
DOCX
DOC
JPG
XLSM
JPEG
TIFF
XPS
HTM
TXT
PNG
TIF
DOTX

I know that the TIFF documents are already compressed, therefore, it is not necessary for the system to try and compress them.
But regarding all of the other file types, does it hurt to specify the default Data Compression of OD77 so
that Content Manager OnDemand will try and compress input files before storing them?

Thanks.

run8

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Re: Compression - Which File Types Should be Compressed?
« Reply #1 on: March 23, 2017, 08:35:38 AM »
We have documents of the following types that we are migrating from CM for i to OnDemand for i:
PDF
XLS
XML
HTML
XLSX
MSG
DOCX
DOC
JPG
XLSM
JPEG
TIFF
XPS
HTM
TXT
PNG
TIF
DOTX

I know that the TIFF documents are already compressed, therefore, it is not necessary for the system to try and compress them.
But regarding all of the other file types, does it hurt to specify the default Data Compression of OD77 so
that Content Manager OnDemand will try and compress input files before storing them?

Not all TIFFs are compressed, most are but check before you decide what to do.
Almost all image formats are already compressed, e.g. JPG,JPEG, TIFF, TIF ,PNG.
Text and XML based  file types are readily compressable, e.g. XML, DOC, DOCX, XLSX, XLS, TXT etc.
AFPDS (especially) and PDF can sometimes be compressed dramatically.
...John Reay
Run 8 Systems Inc.
Toronto

BHUMENY

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Re: Compression - Which File Types Should be Compressed?
« Reply #2 on: March 23, 2017, 10:48:25 AM »
Does it matter if you specify compression for a file type that has already been compressed?
Most of these files are small, so the extra processing is probably negligible.

Justin Derrick

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Re: Compression - Which File Types Should be Compressed?
« Reply #3 on: March 23, 2017, 01:20:33 PM »
If a data type has already been compressed (JPEG, GIF, PDF, most TIFFs), compressing it a second time may make the file LARGER.

There's also a snag with office files (.doc*, .xls*) -- these are actually .zip files containing files full of meta data -- so they probably won't compress at all.

So, for MOST of these document types, you'll want to set the compression to "Disable" which not only prevents compression at load time, it ALSO prevents compression when trying to send the data to the client.

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Alessandro Perucchi

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Re: Compression - Which File Types Should be Compressed?
« Reply #4 on: April 22, 2017, 06:46:54 AM »
Well, if you don't know if the compression will be worth doing it, my advice is to take some sample files and try each compression with the command "arsadmin compress" and compare the compression ratio.

Only then you will be able to have a clear view if you need or not a compression, and if you want a compression which one provides the best compression for you files.

My advice is for one type of files to take a few samples, not only one in order to have a better overview of the gain/loss of each compression algorithm.
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