Why does PST size increase after viewing in preview page?

[hammerhead13]

I have create a pst and mounted it in Outlook 2003. It is 2.7MB. When I mount
it & highlight a message in the Preview pane once I disconnect from it the
File size changed to 2.9MB. Can anyone explain to me why this happens? Is
there any documentation on the MS Website to view on this? Thanks in advance.

 

[Roady [MVP]]

First of all; a 2.7MB pst-file is very very small. The fact that it changed
in size (0.2MB), didn't have anything to do with your selection and could be
caused by normal operation. The pst-file is a database file which requires a
certain amount of white space to function properly. It will automatically
expand and shrink while using it.

 

[VanguardLH]

I have create a pst and mounted it in Outlook 2003. It is 2.7MB. When I mount
it & highlight a message in the Preview pane once I disconnect from it the
File size changed to 2.9MB. Can anyone explain to me why this happens? Is
there any documentation on the MS Website to view on this? Thanks in advance.

Well, did that e-mail you open have external links to content, like
image files? If you optioned OL2003 to show external content or you
selected to allow it then obviously you wanted OL2003 to go retrieve
that additional but external content so it could completely render the
HTML-formatted e-mail. That's my guess since you never showed the raw
source of the e-mail to figure out just what it was.

 

[hammerhead13]

So it is normal for a PST file to Fluctuate in size with just accessing? I
noticed it stated the same size when it was opened and closed but when I
clicked on messages or schedules and viewed them in the preview pane the file
size increased. It varied in size for different PSTs from 200KB - 5MB.

 

[Roady [MVP]]

Yes, it's very normal to fluctuate like that. Even when you think you
haven't done anything, other things are still going on "under the hood"
which writes to the pst-file; last send/receive results, view settings,
indexes, etc...

Pst-files of the sizes that you mentioned are pretty much empty or contain
very little data. It will probably grow with each operation that you do
without saving new items to it. The pst-file itself needs some space to work
with as well ;-)

 

[hammerhead13]

These are plain txt emails for the most part and Calender items.

 

[VanguardLH]

These are plain txt emails for the most part and Calender items.

Access to records in the database are tracked by the Modified timestamp
field in that record. I don't know if the old record is kept and simply
marked with status Deleted (to hide it) or if the Modified field in the
record gets updated. Typically accesses to databases, even when not
updates (writes), can cause record enlargement or increased number of
records which are only removed when a Purge operation (compaction) is
performed. Have you ran a manually compact yet to see if the .pst file
goes back to its original size? Were no other items (e-mails, meeting
requests, appointments, etc.) received or triggered while Outlook was
open when you selected the plain-text e-mail during your test?

Note that Outlook never just "accesses" (reads) the .pst file. Outlook
demands write access to the .pst file. Every time you load Outlook, the
..pst file will be opened in write mode. This is why, for example, you
must remove the read-only attribute from the .pst file if you copy a
backup copy of it from a CD (which is read-only media and results in the
read-only attribute getting set on the file when you copy it from the CD
to the hard drive). When you preview the item, Outlook is writing to
the .pst file, not just reading from it. Outlook always need write
access to the .pst file.