[Info-vax] VMS MAIL: order of DELETE

[Craig A. Berry]

On 10/20/19 5:50 PM, Simon Clubley wrote:
> On 2019-10-20, Volker Halle <volker_halle at hotmail.com> wrote:
>> Phillip,
>>
>> routine mail$cmd_delete in module [MAILSHR] has:
>>
>>       INCR i FROM 1 TO .mail$gl_message_count
>>
>> where mail$gl_message_count is 'Number of messages selected'
>>
>> So if specifying MAIL> DELETE/ALL all the selected mails seem to be
>> deleted in ascending message number order.
>>
> 
> Wouldn't it be more efficient to delete the files in reverse order ?
> 
> That way, if you are deleting a large number of messages at once,
> you don't end up having to shuffle down directory blocks which are
> going to be deleted anyway.

As far as I can remember, deleting mail messages may or may not involve
deleting files, depending on the size of the message.  And even if the
order in the file system has anything to do with the order in which
messages are received (I don't remember how the files get named),
deleting most recent messages first might actually do what you are
suggesting, depending on what the naming convention is.