[Info-vax] VMS MAIL: PURGE/RECLAIM or COMPRESS?

[Hein, Nashua NH]

On Sep 14, 12:44 pm, hel... at astro.multiCLOTHESvax.de (Phillip Helbig---
remove CLOTHES to reply) wrote:
> Which is better?  PURGE/RECLAIM locks the mail file for longer.  Do both
> have ultimately the same effect?

I nice external convert, on your own terms, with tuned FDL is best!


PURGE/RECLAIM will allow you to reuse entirely empty buckets.
As messages are roughly organized by date&time those empty buckets
will happen if you delete messages in time ranges. If you delete one-
sies and two-sies and otherwise just move messages to folders then you
may well end up with a still-in-use message in many bucket, and the
Reclaim will do squat.
But since by default buckets are small (5block) and hold but few
records, it tends to work.
The nice part about reclaim is that the file may reach a more less
stable state in size, with new messages filling up space from
previously deleted messages.

COMPRESS may well be too aggressive. It returns the file with NO space
for new messages, and any and every new message will cause the file to
grow. Slowly, fragmenting the disk in the process.
- use your own FDL with an ALLOCATION matching your period target
- SET FILE/EXTEN=5000 ! Or whatever is half of the period target.

hth,
Hein.