Hi Zoltan! There is a formula to check your 'fragmentation' level to verify Remco's explanation:
SELECT CAST((100 - (CAST(MAX_REDUCTION_MB AS FLOAT) * 256 ) / (CAST(USABLE_PAGES AS FLOAT) - CAST(USED_PAGES AS FLOAT) ) * 100) AS DECIMAL(4,2)) AS PERCENT_FRAG FROM DB Kindest regards, Eric van Loon KLM Royal Dutch Airlines -----Original Message----- From: Remco Post [mailto:[EMAIL PROTECTED] Sent: Tuesday, July 22, 2003 16:42 To: [EMAIL PROTECTED] Subject: Re: Database numbers don't add up On Tue, 22 Jul 2003 10:27:04 -0400 Zoltan Forray/AC/VCU <[EMAIL PROTECTED]> wrote: > TSM server V5.1.6.2 on z/OS. > > Can someone explain why these numbers from a Q DB F=D don't "add up" (at > least they don't make sense to me ?): > > Available Space (MB): 35,160 > Assigned Capacity (MB): 35,160 > Maximum Extension (MB): 0 > Maximum Reduction (MB): 5,372 > Page Size (bytes): 4,096 > Total Usable Pages: 9,000,960 > Used Pages: 4,968,239 > Pct Util: 55.2 > Max. Pct Util: 55.2 > Physical Volumes: 15 > > In summary, it says that of the roughly 35GB DB, only 55% is used. In > round numbers, 20GB is in use. This means that 15GB is not. > > However, the "Maximum Reduction" value is 5GB. > > Where is the other 10GB ? > 'In between', some people refer tot this as database fragmentation. There are appereantly in your case, a lot op pages unused, but that cannot be freed for database reduction. This probably has something to do with how TSM allocates a fresh db page when it needs one, I'm guessing that it tries to allocate pages in a way that leaves you with a as good as possible performance. As long as you don't really need the diskspace, I wouldn't worry. If you really do need the disks, I guess unloading than loading the db will temporarely resolve this problem (and in the end will leavy you with a db that performs far less than currently). > Even if TSM kept the "reduction" values based on the volume sizes (roughly > 2.3GB per 3390-3 volume is what it is reporting), I should still be able > to reduce the size by 6-volumes, or roughly 13GB ! -- Met vriendelijke groeten, Remco Post SARA - Stichting Academisch Rekencentrum Amsterdam http://www.sara.nl High Performance Computing Tel. +31 20 592 8008 Fax. +31 20 668 3167 "I really didn't foresee the Internet. But then, neither did the computer industry. Not that that tells us very much of course - the computer industry didn't even foresee that the century was going to end." -- Douglas Adams ********************************************************************** For information, services and offers, please visit our web site: http://www.klm.com. This e-mail and any attachment may contain confidential and privileged material intended for the addressee only. If you are not the addressee, you are notified that no part of the e-mail or any attachment may be disclosed, copied or distributed, and that any other action related to this e-mail or attachment is strictly prohibited, and may be unlawful. If you have received this e-mail by error, please notify the sender immediately by return e-mail, and delete this message. Koninklijke Luchtvaart Maatschappij NV (KLM), its subsidiaries and/or its employees shall not be liable for the incorrect or incomplete transmission of this e-mail or any attachments, nor responsible for any delay in receipt. **********************************************************************