Re: Oracle & OS related questions...

Then how about the performance IF the data block size of OS not change? i.e. read a data block need one I/O. What is the advantage if the DB_BLOCK_SIZE increase from 2K to 4K while the data block of OS still 2K (need 2 I/O read)?

David

In article <7ue8ol$t4d$1_at_nnrp1.deja.com>,   jdufour_at_my-deja.com wrote:
> The gain depends on the nature of the DB. If an OLTP DB with lots of
> random queries on rows of 2000 bytes or less, probably would not
> benefit performance, in fact, would likely degrade. If more
> batch-oriented or DSS or data warehouse type DB, you would likely gain
> from the larger block size.
>
> Jerry Dufour jdufour_at_home.com
>
> In article <7ue7b2$scn$1_at_nnrp1.deja.com>,
> david_petit_at_yahoo.com wrote:
> > Hello all,
> >
> > I want to ask some questions about the Oracle and OS questions. Hope
> > someone can help.
> >
> > 1) I know that during each I/O, OS reads the data block size from
hard
> > disk to memory. If I doubling the DB_BLOCK_SIZE, is there any
> > performacce gain if the OS block size still not change? For example,
> if
> > I change the DB_BLOCK_SIZE from 2K to 4K, OS still needs two I/O to
> move
> > the data from disk to memory, what are the advantages of setting
> > DB_BLOCK_SIZE from 2K to 4K? And Is is possible to change the data
> block
> > size on Solaris and Windows NT, and how? (or pointing to which web
> site
> > discuss these issues)
> >
> > Thanks,
> > David
> >
> > Sent via Deja.com http://www.deja.com/
> > Before you buy.
> >
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
>

Sent via Deja.com http://www.deja.com/
Before you buy. Received on Mon Oct 18 1999 - 04:52:56 CDT