Re: Optimal db_block

From: Peter Sharman <psharman_at_us.oracle.com>
Date: Mon, 08 Feb 1999 13:55:38 -0800
Message-ID: <36BF5D5A.E900E2C2@us.oracle.com>

Guy

It basically said bigger blocks are generally better for the following reasons:

Shallower, wider index trees
More cheap data transfer per expensive setup Better space efficiency through lower o’hd Diminishing returns kick in at about 16KB

I don't recall seeing anything on the OS block size other than match it with the db block size if you can.

HTH. Pete

Guy Bradet wrote:

> Peter Sharman wrote:
>
> > There has been some work done by Oracle's System Performance Group on this
> > question. From memory, their determination was that you should almost never
> > use 2K (of course, that's the default!), and there are few situations where a
> > block size less than 8K is valuable. As you say, larger sizes still are good
> > for DSS.
> >
>
> Do you remember if it said anything about what the O/S filesystem block size should be?
>
> Guy

Regards

Pete

Peter Sharman                              Email: psharman_at_us.oracle.com
WISE Course Development Manager            Phone: +1.650.607.0109 (int'l)
Worldwide Internal Services Education               (650)607 0109 (local)

San Francisco

"Controlling application developers is like herding cats." Kevin Loney, ORACLE DBA Handbook
"Oh no it's not! It's much harder than that!" Bruce Pihlamae, long term ORACLE DBA

Received on Mon Feb 08 1999 - 15:55:38 CST

Re: Optimal db_block_size