Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Usenet -> c.d.o.server -> Re: object # of extents

Re: object # of extents

From: Sybrand Bakker <postbus_at_sybrandb.demon.nl>
Date: Wed, 28 Jun 2006 22:48:35 +0200
Message-ID: <qmq5a25huamcpfks8cvhjhvbns9p9dlf75@4ax.com>


On 28 Jun 2006 11:28:23 -0700, "Ben" <balvey_at_comcast.net> wrote:

>
>gazzag wrote:
>> Ben wrote:
>> > > Frank van Bortel wrote:
>> > > > Ben schreef:
>> > > > > Running Oracle 9.2.0.5 Ent Ed, DMTs, UNIX AIX5L, compatible parameter =
>> > > > > 8.1.0
>> > > > >
>> > > > On 9i, release 2, you should really get used to locally managed
>> > > > tablespaces with auto segment space management.
>> > > > In that case, you will probably never even *have* 1500 extents!
>> > > >
>> > > > And I start worrying at about 4000 (four thousand) extents. And
>> > > > even then, I doubt it would be "a concern".
>> > > >
>> > > > --
>> > > > Regards,
>> > > > Frank van Bortel
>> > > >
>> > > > Top-posting is one way to shut me up...
>> >
>> > well, how about 8000 then?
>>
>> Other than a perceived excessive extent usage, what "problem" are you
>> attempting to solve?
>
>I was trying to find out if it IS a problem. I'm fairly new to being an
>Oracle DBA and this is something that I ran across, so I didn't know if
>it could possibly cause some problems if there are tons of extents. I
>would imagine if the datafiles for a tablespace are spread across
>several drives and a select had to query data from very many of those
>small extents it could possibly cause an I/O issue, couldn't it?

I/O issues would exist only if the extent size isn't a multiple of db_block_size * db_file_multiblock_read_count, but with autoallocated extents that is no longer an issue..

--
Sybrand Bakker, Senior Oracle DBA
Received on Wed Jun 28 2006 - 15:48:35 CDT

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US