Re: Obvious problems

Jerry Gitomer wrote:
>
> >>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<<
>
> On 4/21/00, 5:25:06 PM, Aaron <asentell_at_my-deja.com> wrote regarding
> Obvious problems:
>
> > I am fairly new to Oracle and need to impress my current employer by
> > analyzing an Oracle database that was installed by a non-Oracle DBA
> > (one of our managers did it, actually). What obvious and potentially
> > big problems should I look for in this small 250 MB database? Here
 are
> > some problems which I am already know to look for:
 

> > * User tables should not be created in the SYSTEM tablespace
> > * The pct_increase attribute for tablespaces and tables should
 probably
> > not be the default of 50. A value of 1 to allow for automatic
> > coalescing of free extents is what I would recommend.
>
> You are better off with uniform sizing. This means every extent of
> every table in a tablespace is the same size. To accomplish this
> don't include a storage clause in your table definitions and use
> PCTINCREASE 0. This will minimize the maintenance requirements
>
> > * Tables should be stored over a minimum number of extents.
>
> Given that the minimum is one, this is no longer true. My personal
> preference is to keep it low, but when I reorganized tables with 50 or
> more extents so that they had less than five extents I saw no
> improvement in performance.
>
> > * The sys, system, and internal passwords. (Question: Should these
> > <all> be changed from their defaults?)
>
> Change them. All it takes is one user who just finished reading
> Oracle Data Base Administration in 24 hours (My apologies to SAM's) to
> log on as System/Manager and accidentally drop a table ...
>
> > * Multiplexing of the control file and online redo logs.
 

> > If there is anything else you can think of, or if I have stated
> > anything incorrectly, please let me know. Oh yeah, I forgot to
 mention
> > that this database is running on Windows NT if that makes any
> > difference.
>
> If the default number of datafiles for NT is still 29 you might want
> to recreate the database using a custom database creation script (the
> GUI installer doesn't give you the option of changing the value)
>
> I also suggest that you pick up a copy of Oracle 101 by Carson,
> Theriault, and ??
> (I probably have the title screwed up as well).
>
> > Thanks!
 

> > Sent via Deja.com http://www.deja.com/
> > Before you buy.

Whilst I certainly agree that a single extent is no longer a major issue, more than 20 for lots of objects can cause a few dilemmas with some of the internal dictionary clusters.

Although a locally managed tablespace takes a lot of that hassle away thankfully...

HTH

-- 
===========================================
Connor McDonald
http://www.oracledba.co.uk

We are born naked, wet and hungry...then things get worse