txn performance penalty

[Greg Louis]

Calendar time, on an otherwise idle machine with 512Mb RAM and 1Gb
swap, to process 545 spam starting after cold boot (memory is clear):

0.92.8: 51 seconds
0.93.1 with defaults: 489 seconds
0.93.1 with DB_TXN_NOT_DURABLE: 492 seconds

This was with db-4.2.52.  Processing involved scoring each message
individually (with formail) and then scoring the same mbox with a
single bogofilter run (-vM).  The idea is to scan the spams and
register any false negatives, then rescan to check the result; but in
these runs there were no fn and so no messages were registered.  Yet
all the __db.* files, lockfile-p and wordlist.db were updated during
the 0.93.1 runs.  The bulk of the time was consumed in disk activity.

I can't take the time now to investigate further, and I'll be offline
for a few days after today.

-- 
| G r e g  L o u i s         | gpg public key: 0x400B1AA86D9E3E64 |
|  http://www.bgl.nu/~glouis |   (on my website or any keyserver) |
|  http://wecanstopspam.org in signatures helps fight junk email. |