Oracle FAQ Your Portal to the Oracle Knowledge Grid

Home -> Community -> Mailing Lists -> Oracle-L -> Re: Veritas Quickio and DB_BLOCK_SIZE

Re: Veritas Quickio and DB_BLOCK_SIZE

From: Jonathan Lewis <>
Date: Wed, 03 Oct 2001 12:19:27 -0700
Message-ID: <>

Is this the thread where Thomas says something about:

>I've done the same (recommend 2k blocks). It is true. I am serious.
2k is
>appropriate in some cases. some reasoning:

        NOTE -- 'in some cases'
        NOTE -- 'some reasoning'

and my follow-up post contains:

> Me too -
> Some more reasons:

        (reasons cut)

> It all comes down to knowing the application,
> the environment, the usage patterns, the
> data distribution, and doing the arithmetic.
> Have to say though, that unless the file system
> allows for 2K writes (e.g. with Veritas direct I/O
> option) then you generally have to choose
> between an optimum Oracle blocksize and
> an optimum O/S blocksize or move to raw devices

    NOTE -- 'some more reasons'
    NOTE -- 'doing the arithmetic'
    NOTE -- the warning about Oracle and O/S block sizes.

Neither Thomas nor I made a throwaway remark suggesting a specific block size was appropriate - we both stated that we had on occasions used 2K where appropriate. Nor did we add a valueless caveat about 'the application being appropriate', we actually gave concrete reasons why an application may or may not be appropriate.

Jonathan Lewis

Host to The Co-Operative Oracle Users' FAQ

Author of:
Practical Oracle 8i: Building Efficient Databases

Screen saver or Life saver: Use spare CPU to assist in cancer research.

-----Original Message-----
To: Multiple recipients of list ORACLE-L <> Date: 03 October 2001 20:03

|By the way, you are agreeing and disagreeing with
|Jonathan Lewis at the same time. The index efficiency
|on small block size is Jonathan's point he made a
|couple of years ago when he was stating why he
|recommends a 2k block size on an OLTP type database.
|The other index point (scanning an index on a small
|block size) is from Thomas Kyte on the same
|thread...If you disagree with him, you can write him
|an e-mail so you can correct him.

Please see the official ORACLE-L FAQ:
Author: Jonathan Lewis

Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists
To REMOVE yourself from this mailing list, send an E-Mail message
to: (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).
Received on Wed Oct 03 2001 - 14:19:27 CDT

Original text of this message