Number of extents related with performance?

Hi all,

      I've read news and documents about the effect on the performance when the number of extents of object is increased. Most of it (even on Oracle Metalink) just mentioned that the performance is not related with the number of extents (except dropping and truncating tables). However, when I query the table that has about 800000 rows (about 200M storage spaces) with over 100 extents (extent size is 32K), it takes about 10 second to return the number of rows. When I increase the extent size to 64M (number of extents is now 3), it just takes 2 seconds.

        Could anyone tell me is there any relationship between the performance and the number of extents of an object? (in my case, both tables are newly created, so no fragmentation) It seems that, as my case, decrease the number of extents can increase the query performance.

Thanks,
David Received on Fri Dec 29 2000 - 02:44:54 CST