Re: index fragmentation

From: Roman Starek <starek_at_pluto.spsselib.hiedu.cz>
Date: 19 Sep 2000 08:35:12 GMT
Message-ID: <8q78g0$t2f$1@crax.cesnet.cz>

>
> but of course you were also going to quote that number of extents
> typically will have absolutely no impact on performance...
>

I dont think so. A have some reasons for my opinion.

Big number of extents is problem for database. The more extents the bigger dictionary tables are. This brings big performance penalty specially for development enviroments. I know what is this about. Our developing enviroment contains 98000 objects in it.
Big number of extents for index is not good for fast index scan.
Big number of extents usually mean that extents are distributed across all tablespace. This means that using index requires more work to be done through discs.

Generally I think number of extents is not problem for small number of extents < 10 maybe 20.

Starous Received on Tue Sep 19 2000 - 03:35:12 CDT