Well, since no one else has ventured an answer, I'll take a SWAG in hope that someone will at least provide more information in shooting it down!
My DB is 28 GB on AIX, and my buffpool is only 192,000; I agree that 327680 is QUITE high for a 2.5 GB, Windows or not. You say that a consultant rebuilt your DB - I assume you are talking an UNLOAD/RELOAD? If so, then what I would do is - nothing, at least for a while. Based on what little has been published about the structure of the TSM DB, I know it is a b-tree. When you reload a DB of that type, usually what happens is that the DB becomes, shall we say "tightly packed", and a good bit of DB activity takes place right after a DB reload as the tree splits off new empty "leaves" to accomodate new incoming records. If that is what is happening here, then over time your DB cache hit should gradually get better again, as the DB "resettles" itself into normal adding patterns. What I would do is reset the cache statistics, watch it for a couple of days; then reset them again, watch it for a couple days; see if it gets better on its own after a week or two. OK, that's the only far-fetched answer I can come up with. Any body else had strange numbers after a DB rebuild? ************************************************************************ Wanda Prather The Johns Hopkins Applied Physics Lab 443-778-8769 [EMAIL PROTECTED] "Intelligence has much less practical application than you'd think" - Scott Adams/Dilbert ************************************************************************ -----Original Message----- From: MORGAN TONY [mailto:[EMAIL PROTECTED]] Sent: Monday, February 11, 2002 4:19 AM To: [EMAIL PROTECTED] Subject: Cache Hit Rate, Bufpoolsize Size and NT Another week another problem... Hi Guys!! I have a DB (shown Below) which I am having trouble with. The Cache Hit % was static for months at 98%+, but since the database was rebuilt by a friendly consultant (nice bloke!) I have been unable to achieve consistant results above the mid 90's. The Bufpoolsize parameter has been raised in stages to its current high of 327680 .. this does not appear to be having the desired effect. Server: Dual Xeon 700Mhz (Dell 8450) running NT 4.0 SP6a TSM V4.1.1.0 Selftune bufpoolsize is OFF DB is spread over 5 files of 1GB on a Fast Raid 5 (R/WB Cache enabled) I have two questions for our assembled throng. 1) What do YOU think is a reasonable figure for Bufferpoolsize on NT for a 2.5b DB?? (I regard 327680 as quite high) 2) What else could be wrong? Any help will be high appreciated Many Thanks Tony Morgan Available Space (MB): 5,120 Assigned Capacity (MB): 5,120 Maximum Extension (MB): 0 Maximum Reduction (MB): 2,080 Page Size (bytes): 4,096 Total Usable Pages: 1,310,720 Used Pages: 676,424 Pct Util: 51.6 Max. Pct Util: 51.8 Physical Volumes: 10 Buffer Pool Pages: 81,920 Total Buffer Requests: 29,893,741 Cache Hit Pct.: 93.42 Cache Wait Pct.: 0.00 Backup in Progress?: No Type of Backup In Progress: Incrementals Since Last Full: 0 Changed Since Last Backup (MB): 0.09 Percentage Changed: 0.00 Last Complete Backup Date/Time: 02/11/2002 08:00:16 ============================================================ This e-mail and any files transmitted with it, are confidential and intended solely for the use of the addressee. The content of this e-mail may have been changed without the consent of the originator. The information supplied must be viewed in this context. If you have received this e-mail in error please notify our Helpdesk by telephone on +44 (0) 20-7444-8444. Any use, dissemination, forwarding, printing, or copying of this e-mail or its attachments is strictly prohibited.
