Re: CBO cost and avg_row_len

On 9 Jul 2003 08:34:56 -0700, ydias_at_hotmail.com (dias) wrote:

>Hi,
>
>Can someone explain when the CBO takes into account the value of
>avg_row_len to estimate an access plan cost ?
>
>I suppose that the CBO uses this value to estimate the cost for a
>table scan, in combination with the number of blocks and the value of
>db_file_multiblock_read_count ?
>
>Thanks

It doesn't. It would also be unnecessary, as a block is a block is a block and a table scan is a table scan is a table scan. Oracle will always read a complete block. The number of blocks in use is taken into account.

Sybrand Bakker, Senior Oracle DBA

To reply remove -verwijderdit from my e-mail address Received on Wed Jul 09 2003 - 12:40:51 CDT