Subject: TENEX mailbox slow to delete?

From: Andy Poling <[email-masked]>
Date: Mon, 25 Jul 1994 10:57:16 -0400

I have recently changed to using a tenex mailbox for better performance
reading my rather large mailbox.  I use IMAP (IMAP2bis server that came with
PINE v 3.89) in PINE (v 3.89) to read my mail. 

The problem I have noticed, since changing to a tenex mailbox, is that every
delete (just hitting "d") seems to take about 1 second (the expunge is very
fast when I get to it).  You can imagine how frustrating it is to try to
delete ~300 consecutive messages. 

Am I missing something or is this a design fault in the tenex "driver" 
code?

-Andy

Andy Poling                              Internet: [email-masked]
UNIX Systems Programmer                  Bitnet: ANDY@JHUNIX
Homewood Academic Computing              Voice: (410)516-8096    
Johns Hopkins University                 UUCP: uunet!mimsy!jhunix!andy

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From: Mark Crispin <[email-masked]>
Date: Tue, 26 Jul 1994 09:57:13 -0700

One possible explanation for your delete problem may be in your system's
implementation of the fsync() call.  The tenex driver uses update mode I/O; a
delete is simple the change of a single byte of a file, followed by an fsync()
to force the update to be written to the disk.  An aggragate delete (delete of
multiple messages at the same time -- this is supported in Pine 3.90) would
update all the bytes before doing the fsync().

Some operating systems implement fsync() as sync() which can be quite bad.  If
this seems to be the problem, try disabling the fsync() calls.  This may
improve performance, at the risk of being vulnerable to lost updates in the
event of a crash.