Re: Db_block_size

Thanks, Chris, Rachel and Guy for the answers. Actually we don't have production database(anytime), so I don't even have the archive log files. My question is what's the benefits of increasing the db_block_size, what is the limit?

    I recreated a database of 16K db_block_size yesterday and the performance increased about 50%. (Our application is about sending emails to as many customers as possible, basically just batch processing).

    Thanks.

Eric Fang   

• Chris Royce <Chris_at_Royce.net> wrote:
  > Rachel,
  >
  > I definitely concur on the PLANNING part. I will
  > be 'resizing' our
  > Production Oracle Applications database this weekend
  > and although I am fully
  > prepared - it is still an intimidating task. Aside
  > from the obvious backups and
  > rollback procedures, I have practiced a number of
  > times and have had several
  > complete 'dress rehearsals'. There are any number of
  > 'gotchas' that cannot
  > always be anticipated. Between interdependencies,
  > cross grants, compressed
  > extents, data file size changes, SGA values that
  > change because of the block
  > size etc. etc. never mind the time it takes to do
  > the export, import, rebuild
  > indexes and then check thousands of lines of logs
  > as well as the status of your
  > objects. Then you can make sure your applications
  > still work. Not for the 'faint
  > of heart'. Also I might add - I resized our
  > development environment first and
  > had the developers thrash it around for a week
  > before I did the same in our test
  > environment - where I had a full integration process
  > take place. Absolutely
  > essential that PLANNING and preparation is observed.
  >
  > My 2 cents worth !!
  >
  > OK BYE
  >
  > Rachel Carmichael wrote:
  >
  > > well you can, sort of. Full database export, trash
  > the existing database,
  > > rebuild it with the new block size, remember to
  > adjust the init.ora
  > > parameters that will be affected by the new block
  > size, full database import
  > >
  > > But it is NOT elegant or quick. Makes a good case
  > for PLANNING before you
  > > actually build anything.
  > >
  > > Rachel
  > >
  > > >From: guy ruth hammond <grh_at_agency.com>
  > > >Reply-To: ORACLE-L_at_fatcity.com
  > > >To: Multiple recipients of list ORACLE-L
  > <ORACLE-L_at_fatcity.com>
  > > >Subject: Re: Db_block_size
  > > >Date: Thu, 08 Jun 2000 00:56:08 -0800
  > > >
  > > >Eric Fang wrote:
  > > > >
  > > > > I tried to increase the db_block_size from 8k
  > to 16k.
  > > > > What's the maximum block size allowed on NT 4
  > > > > serverice pack 5 and Soloris 2.4. Thanks.
  > > >
  > > >Eric,
  > > >
  > > >You can't change the block size after a database
  > has been created.
  > > >
  

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