From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.emacs.gnus.general/5848 Path: main.gmane.org!not-for-mail From: bmiller@cs.umn.edu (Brad Miller) Newsgroups: gmane.emacs.gnus.general Subject: Re: nndb mailing list? Date: 03 Apr 1996 21:18:59 -0600 Organization: UMN Sender: bmiller@cs.umn.edu Message-ID: References: NNTP-Posting-Host: coloc-standby.netfonds.no Mime-Version: 1.0 (generated by tm-edit 7.43) Content-Type: text/plain; charset=US-ASCII X-Trace: main.gmane.org 1035146391 1554 80.91.224.250 (20 Oct 2002 20:39:51 GMT) X-Complaints-To: usenet@main.gmane.org NNTP-Posting-Date: Sun, 20 Oct 2002 20:39:51 +0000 (UTC) Cc: ding@ifi.uio.no Return-Path: ding-request@ifi.uio.no Original-Received: from ifi.uio.no (ifi.uio.no [129.240.64.2]) by deanna.miranova.com (8.7.5/8.6.9) with SMTP id TAA04411 for ; Wed, 3 Apr 1996 19:43:07 -0800 Original-Received: from mail.cs.umn.edu (mail.cs.umn.edu [128.101.149.1]) by ifi.uio.no with ESMTP (8.6.11/ifi2.4) id for ; Thu, 4 Apr 1996 05:19:13 +0200 Original-Received: from caesar.cs.umn.edu (bmiller@caesar-224.cs.umn.edu [128.101.224.60]) by mail.cs.umn.edu (8.7.5/8.6.12) with ESMTP id VAA03212; Wed, 3 Apr 1996 21:19:07 -0600 (CST) Original-Received: (bmiller@localhost) by caesar.cs.umn.edu (8.6.12/8.6.12) id VAA09652; Wed, 3 Apr 1996 21:19:05 -0600 Original-To: dblacka@fuentez.com In-Reply-To: Dave Blacka's message of 29 Mar 1996 12:13:38 -0700 Original-Lines: 39 Xref: main.gmane.org gmane.emacs.gnus.general:5848 X-Report-Spam: http://spam.gmane.org/gmane.emacs.gnus.general:5848 >>>>> "Dave" == Dave Blacka writes: >>>>> "Joe" == Joe Hildebrand writes: Joe> Also BTW, we did some more testing on the differences between gdbm and Joe> berkeley db. Gdbm wins *big* on disk space (like one less digit in Joe> the bytes column), and is not noticeably slower. It will probably be Joe> the default in 0.8. We'll also include a script to convert one to the Joe> other. Dave> Ok. Joe lied here a bit. GDBM does actually win big on disk space: Dave> Berkeley DB isn't really very space efficient when the data you are Dave> storing has widely different sizes (like mail bodies), so the Berkely Dave> DB file grows to enormous size. For instance, I probably have at most Dave> 1 Meg of mail stored in a 7 MB mail.db file. GDBM gets you much Dave> closer to the actual size of the data. However, GDBM and Berkeley DB Dave> only have comparable speeds when you are hitting a local disk. In my Dave> testing so far, GDBM suffers from incredible performance problems over Dave> NFS, while Berkeley DB behaves about the same. Thus, if you are Dave> storing your mail.db file on a local disk, switching over to GDBM is Dave> probably a real good idea, otherwise it would probably be best to wait Dave> until Joe and I rework the whole backend of nndb. The GroupLens Better Bit Bureau uses gdbm as its database, and I can vouch for the fact that performance over NFS is really really bad. Also, if you happen to get into a situation where you are frequently updating the data associated with one key, the database will start to grow all out of proportion. The only solution to this seems to be to call gdbm_reorganize, but that is terribly slow. I've had some database files go from 46Meg back down to 8Meg with one call to reorg! \Brad ---------------------------------------------------------------------------- Brad Miller | e-mail: bmiller@cs.umn.edu University of Minnesota | phone: (612) 626-8396 Department of Computer Science | www: http://www.cs.umn.edu/~bmiller EE/CS 5-244 | ---------------------------------------------------------------------------- ** Save USENET Try GroupLens: http://www.cs.umn.edu/Research/GroupLens ** ----------------------------------------------------------------------------