Re 1: No. Cache Fusion is no longer an issue. It's free.
Re 1: Yes. Cache Fusion is of course still a cost. It's neccessary,
therefor it is, and therfor it has a cost. You can call it anything you
like (and people do), but data partitioning still, after all these
years, minimize pinging.
Re 2: No idea. I suspect it doesn't matter one iota whatsoever. It's
just "I've heard this" vs "I've heard that".
Re 3: Why would you want to disable the excellent index skip scan? Good
luck with AUM and ASSM. This test can't fail, as long as you're using
anything Oracle recommends.
Re 4: Forget best practices. Forget silver bullets. They work for one
site, but never for another. There are only worst practices.
Good luck.
Mogens
VIVEK_SHARMA wrote:
Folks
A 4-node RAC BIG benchmark with Oracle 10g / AIX 5.3L using a Hybrid Banking App. is underway.
*Qs1 Does Cache fusion(Traffic between the nodes thru the interconnects) continue to be an expensive operation in Oracle 10g?*
To minimize Cache fusion, Manually Transactions have been grouped such that transactions accessing different DB Server Nodes access different respective Table partitions (& NOT the same Table partition). Thus Different Object BLOCKS are accessed in different DB Server nodes.
NOTE – Partitioning of heavier underlying tables has been done such that different partitions lie in DIFFERENT Tablespaces (& hence datafiles).
*Qs2 Is Low Latency Protocol - LLT protocol (of Veritas) equivalent or something similar available with GPFS?*
Currently default (UDP) is being used.
NOTE - A Past benchmark done by us on SUN using VXFS (Veritas) with both Low Latency Protocol (LLT) & User Datagram Protocol (UDP, Default) showed LLT had a *98% Lower interconnect utilization* versus UDP.
*Qs3* Any additional init.ora parameters for performance apart from the following which have been set?
db_writer_processes=16
db_cache_advice=OFF
event='10196 trace name context forever, level 10' (to disable index skip scan)
_library_cache_advice = FALSE
_log_simultaneous_copies 256
_b_tree_bitmap_plans = FALSE (as NO Bitmap indexes exist)
_check_block_after_checksum TRUE
_system_trig_enabled FALSE (Benchmark Has NO need for Triggers)
_wait_for_sync TRUE
NOTE - Standard features i.e. AUM, Tempfiles & ASSM are being used.
*Qs4 Other best practices to deploy?*
Will provide Statspack, Other diagnostics info. as needed.
Thanks indeed
*Configuration*:-
APP & DB machines – *P5* series
Application Hybrid – (OLTP + Batch nature of Trans).
Oracle 10.2
AIX 5.3
Filesystem GPFS
Storage Box DS8300
Hardware RAID 1+0
Underlying Hardware Stripe Unit Size 64 KB
Overlying Logical Volume Manager Stripe Unit Size 32 MB (S.A.M.E.)
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