Re: Defragmentation

On 18 Sep 1998 07:56:07 GMT, "Robert Jungerius" <rjungerius_at_death-to-spam.cetecint.com> wrote:

>Hello, I'm a Oracle DBA working with Oracle 7.3.4 on the NT4 platform.
>The only way of defragmentation I know of is to export, drop user, create
>user and import.
>This is impossible with databases of 10Gb or more, because the downtime is
>unacceptable and the
>diskspace needed for this operation is outrageous!
>I'm having serious problems keeping the databases of all customers running
>smoothly!
>
>How do you defragment a very large database?
>And does anybody have some tips concerning performance tuning?

Tablespace fragmentation *should not* have any performance impact on well managed database. There are two *excelent* papers about this topic available at http://www.europa.com/~orapub/papers/pmain.htm : - Oracle7 Server Space Management (by C.V.Millsap) - Avoiding A Database Reorganization (by C.A.Shallahamer)

Read those two papers carefully, then take a time and organize your database as sugested there. This will be only one-time-task, othervise you'll be forced to reorganize your database over and over again.

BTW, the old mith "Performance is degraded when tables/indexes consist of more then 1 extent" has nothing to do with reality!

>Thanx in advance.
>
>Robert Jungerius,
>DBA, Software Engineer @ CETEC BV
>rjungerius_at_yahoo.com

Regards,

--
Jurij Modic <jmodic_at_src.si>
Certified Oracle7 DBA (OCP)
================================================
The above opinions are mine and do not represent
any official standpoints of my employer