Re: Oracle vs filesystem block size

Are you saying that the HP default is normally 8K? Where could I find this documented?

The Oracle block size for HP 2K - I have seen this documented in the install guide.

We currently run under the Logical Volume Manager, but are thinking of going to raw devices. Would happen to have the name of the HP Oracle Manager?

Thanks
Steve Lemme
DBA/System Manager
Motorola MOS12

-- 
When you are in it up to your ears....
Keep your mouth shut!
rp1399_at_email.sps.mot.com




In article <37o2he$ive_at_ticsa.com>, gavin_at_durban.vector.co.za (Gavin Maltby,
Vector Durban) wrote:



> >Why do you prefer 8K blocks to 2K blocks?  When doing table scans the parameter


> >db_file_multiblock_read_count kicks in and can be adjusted larger in response to

> >small blocks giving maximum I/O throughput.  On the other hand when doing single

> >row retrieval, such as indexed retrieval, won't the smaller I/O complete faster?

> >

> Well somewhere (I think the 7.0.15 config and installation guide for Solaris)

> Oracle says the db_block_size must be a multiple of the filesystem block size.

> Since db_block_size has a max of 8K and we want at least 8K filesystem blocks

> there seems little choice.  I didn't see the same comment from Oracle in the

> config guide for HP (but didn't look hard).  The thing is that HP-UX 9 defaults

> filesystem block to 8K and the default Oracle block size is 2K (same values

> hold on Solaris 2.3) which contradicts their suggestion!

> 

> >Another option to consider on HP/UX is to use the logical volume manager to

> >create raw volumes, and take the file system out of the picture completely.  This

> >was the approach stongly recommended by Oracle's Product Manager for HP at IOUW.

> >

> This is being considered.  Some say the difference is not as marked with Oracle 7

> as for 6.  Apparently a future release of OmniBack is designed to work with

> raw devices to simplify backup of this type of datafile.

> 

> Cheers

> 

> Gavin

> 

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