Path: news.cambrium.nl!textnews.cambrium.nl!feeder3.cambrium.nl!feeder4.cambrium.nl!feed.tweaknews.nl!news2.euro.net!newsfeed.freenet.de!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: Robert Klemme Newsgroups: comp.databases.oracle.server Subject: Re: Are there performancebenefits to reorganizing database-using export/import? Date: Tue, 11 Nov 2008 08:33:37 +0100 Lines: 20 Message-ID: <6nsqqlFnkstU1@mid.individual.net> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Trace: individual.net bH0hxkbUYMjralSDfuq6Lw1jIiFk95AK4q/9TpSVv4SKcjcMg= Cancel-Lock: sha1:hPVN2rebSiXTv57VHVKBX11MlPk= User-Agent: Thunderbird 2.0.0.17 (Windows/20080914) In-Reply-To: X-Antivirus: avast! (VPS 081110-1, 10.11.2008), Outbound message X-Antivirus-Status: Clean Xref: news.cambrium.nl On 10.11.2008 21:52, zigzagdna@yahoo.com wrote: > Are there any benefits to reorganize database using export/import, > i.e., we will do a full export of existing database and then delete > all objects from application schemas and do schema imports. > I have heard different views on reorganization. Some people say it is > useless, some people say it can improve performance since data will be > compacted in fewer blocks. Also agree with Joel: First you should determine whether physical properties (block usage etc.) are actually limiting performance. Assuming that this has been established, an important question is: how much effort does this reorganizing take and how long does the effect last? If it takes a day (during which you might have to go offline) but the effect is gone after a week because of the nature of your workload, it's probably not worth the effort and risk. Kind regards robert