From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alan Cox Subject: Re: Question regarding to store file system metadata in database Date: Sun, 19 Mar 2006 23:06:25 +0000 Message-ID: <1142809585.14592.2.camel@localhost.localdomain> References: <4ae3c140603182048k55d06d87ufc0b9f0548574090@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Return-path: Received: from outpipe-village-512-1.bc.nu ([81.2.110.250]:21428 "EHLO lxorguk.ukuu.org.uk") by vger.kernel.org with ESMTP id S1751178AbWCSW7p (ORCPT ); Sun, 19 Mar 2006 17:59:45 -0500 To: Xin Zhao In-Reply-To: <4ae3c140603182048k55d06d87ufc0b9f0548574090@mail.gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Sad, 2006-03-18 at 23:48 -0500, Xin Zhao wrote: > database system. I ran a test on a mysql database: I inserted about > 1.2 million such kind of records into an initially empty mysql > database. Average insertion rate is about 300 entries per second, Thats extremely slow for a file system. > Then I am a little curious why only few people use database to store > file system metadata, although I know WinFS plans to use database to > manage metadata. The one well known example of a database as file system (or was well known) was the Pick OS (now defunct although the database system lives on). They did manage to build an OS which had a database as a file system. The thing is a database and a file system are the same thing anyway. You'll find the same structures like B trees used in some for example. They are just optimised for different kinds of queries. If you want to know whether a db as fs works , build a prototype and see - you've already taken the first step and with FUSE you can prototype the rest in user space. Alan