Re: datablock sizing

From: <sybrandb_at_yahoo.com>
Date: 5 Mar 2004 03:04:26 -0800
Message-ID: <a1d154f4.0403050304.a50c748@posting.google.com>

vissuyk_at_yahoo.com (Vissu) wrote in message news:<2bedd6a7.0403041956.3935854e_at_posting.google.com>...
> Hi All,
>
> Thank you for your feedback on # of tablespaces. Can anyone share some
> experiences on sizing the data block ?.
>
> Assuming that the biggest row I would have takes up about 2K, what
> should be the size of data block? I am debating between 8K and 16K. Is
> there a rule of thumb as to how many rows should fit in a data block?.
>
> Thanks a lot in advance,
>
> Vissu

It really depends on the nature of your application. Oracle will always read a block, even if you need a single row. Consequently if you run an OLTP app and your blocksize is 16k, and you retrieve only 1 row, you waste 14k (according to your figures). If 8k you only waste 6k. If you have a warehouse app, 16k might help you. In 9i you can have tablespaces with different blocksizes.

Sybrand Bakker
Senior Oracle DBA Received on Fri Mar 05 2004 - 05:04:26 CST