Re: ORACLE Performance Tuning - Your experiences

I'm not a model DBA but here are my answers.

> Which DB_BLOCK_SIZE are you using?

We went with 4.096 bytes because that's a physical read on our server (RS/6000).

> What is your value of DB_MULTI_FILE_READ_COUNT?
Don't know! :-}

> Which formulas do you use for the determination of parameters in the
> storage clause?

I like to set initial to 100K and next to 1M. That way if it's a small table it takes one extent, if it's larger it usually won't need more than a few additional extents. I run DFRAG once a week and it moves everything into the primary extent for fragmented tables, so there seems little to gain in sweating out a precise estimate before the table is loaded.

> Which parameters do you monitor and how often do you monitor them?
I keep a close eye on amount of freespace in each tablespace, and compare the size of the largest freespace extent in a tablespace to each object's value for its next extent to find objects that would have problems if they took an extent. I also watch the total extent count for all objects, though in production DFRAG makes that unnecessary. DFRAG can't degragment freespace extents so I watch them more closely since I have to do them manually with EXP and IMP.

> How do you find out about your current workload?
I use BSTAT and ESTAT to get a count of the maximum number of concurrent sessions each day, and graph it monthly.

Paul de Anguera, City of Seattle / HRIS Received on Fri Aug 09 1996 - 00:00:00 CEST