Re: my max db_file_multiblock_read_count is 128.. why?

yong321_at_yahoo.com (Yong Huang) wrote in message news:<b3cb12d6.0208271218.5b2b6348_at_posting.google.com>...
> andreyNSPAM_at_bookexchange.net (NetComrade) wrote in message news:<3d6a6e60.1484346567_at_news.globix.com>...
> > [lroot/dragon@: ]echo 'vol_maxio /D' | adb -k
> > physmem 1390ee
> > vol_maxio:
> > vol_maxio: 512
> > (256K)

...
> > Oracle Block size=4K
> >
> > So I'd expect my max multi_block_read to be 64 (or even 32, not 100%
> > sure if maxphys has anything to do w/ vxfs)
> >
> > however
> > multiblock_read_test.sql (from Steve Adams/ixora.com.au)
> > shows that it's 128

...
> level, i.e. the file system level, I/O size. In your case, your vxfs
> I/O size is 512K, the same as
> db_file_multiblock_read_count*db_block_size. According to

My mistake. I should say: in your case, your vxfs I/O size is 512 units or 256K (unit of vol_maxio is 512-byte sectors according to Veritas manual). Ignore my "the same as...".

I still would expect a performance plateau when your db_file_multiblock_read_count reaches 32. Can you try?

Yong Huang Received on Wed Aug 28 2002 - 16:31:34 CDT