Re: Oracle Block Size and Solaris 2.6

at http://www.zeda.com/oracle.html there is an Oracle paper on VLDBs. In the paper there is a discussion of data block size. Larger data block sizes prevent some row chaining, it asserts. Further, index performance is inversely proportional to the height of the b-tree. Bigger blocks used by an index results in a wider, shorter tree. Also, getting fewer blocks requires less i/o than more, smaller blocks. However that depends on whether you are mostly getting a large set of blocks. Of course if your data blocks are bigger, you may have more rows in each block, meaning a better hit if you want two rows in the same block. However you might need to define larger initrans for tables if there are many rows per block for the table.

Paul_at_Matthews.Com wrote:
: Is there a general rule of thumb for the Oracle Block Size on Sun Sparc 2000
: running Solaris 2.6? I would have thought 8- or 16-KB, but the previous DBA
: said 2-KB would be better with Solaris 2.6. Any recommendations?

: Is there an easy way to optimize block size other than by trial and error?
: Thanks,

: Paul Matthews

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Received on Sun Dec 06 1998 - 18:11:28 CST