Compressed file question

  • Thread starter Thread starter Academia
  • Start date Start date
I did some testing and it appears that the files Disk Cleanup compressed
have the compress property bit set.

And that opening such a file, modifying it and resaving it leaves it
compressed.

Is that your understanding?
 
The file is "compressed" on the disk, it is stored compressed, it it
"uncompressed" into memory for use. It remains compressed on the disk
with the "compressed" attribute set. Force an uncompressed and it will
remain that way until you or the "Clean Up" utility sets compress on it
again.
 
I found a .DOC word document that was compressed.
Opened it, changed it and selected save changed document in Word. The date
changed but the size and size on disk didn't.

Did the same with another file but used Notebook change and to save the
changed contents. Again the date changed but the sizes shown by Properties
didn't.

Appears that all files compressed by Disk Cleanup have the compressed
attribute checked in it's properties.

How did you mean to "Force an uncompressed"?

Thanks for helping
 
R-click the file in Windows Explorer, Properties, Advanced, UNcheck
"Compress contents........."

As to the size on disk, it won't change UNTIL the contents need another
cluster to hold the file.
 
IMO you're overthinking this too much. Assuming you
have 4k cluster sizes, until the file change is enough
to cross into another sector or dropy by a sector, the
file size display won't change. Explorer is basing its
reported sizes on clusters used, not actaul bytes. If
a cluster gets 1 byte stored into it, even though it
could hold 4k, it's not available to any other program
except the one that owns it, so this number is more
accurate w/r to space "occupied" w/r to space left on
the drive. Look at the overal file sizes in explorer
and how "neat" they are, and it'll become clearer to
you. I have oversimplified my explanation for ease of
description, but to give you the gist of things.

HTH

Pop`
 
The size on disk was about 20K smaller - because of compression I assume -
so I used that as an indicator of the file getting uncompressed on the disk.


I believe my tests have shown me that once the cleanup has compressed a file
it will remain like that even if an app makes changes to it.

Thanks for your input
 
The size on disk was about 20K smaller than the file size - because of
compression I assume - so I used that as an indicator of the file getting
uncompressed on the disk.


I believe my tests have shown me that once the cleanup has compressed a file
it will remain like that even if an app makes changes to it.

Thanks for your input
 
Your "tests" verify what actually happens.
The size on disk was about 20K smaller - because of compression I assume -
so I used that as an indicator of the file getting uncompressed on the disk.


I believe my tests have shown me that once the cleanup has compressed a file
it will remain like that even if an app makes changes to it.

Thanks for your input
Click to expand...
 
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