RE: Common Oracle RDBMS Misconceptions

1. A full table scan is a bad thing
2. the order of things in the FROM/WHERE clause matters (is true in the RULE-based world)

-----Original Message-----
Sent: Tuesday, June 26, 2001 2:27 PM
To: Multiple recipients of list ORACLE-L

1. If an index exists, it will always be used.
2. It is ALWAYS a database problem.

Terry

Jeremiah Wilton wrote:

> All right folks, I'm collecting misconceptions, of the type held by
newbies and
> oldtimers alike. My OOW proposal this year is for a presentation and
paper on a
> whole laundry list of these things, similar to what I wrote for hot
backup. I
> want to share what I have so far and solicit input for your favorites (pet
> peeves). I most certainly will credit individuals and this list for any
ideas I
> glean.
>
> So far my favorite misconceptions are:
>
> * Hot backup stops writing to datafiles
> * All network communication is done through the listener
> * Always 'switch logfile' after (before, inbetween) hot backups
> * Media recovery is required if you crash during backup mode
> * Cold backup once a week ("just in case," "as a 'baseline'")
> * Export is a good way to back up your database
> * Shutdown abort is bad, crash recovery time is as long as 'shutdown
immediate'
> * Listener.log/alert.log clearing confusion
> * ORA-1555 can be solved by setting transaction (use specific rollback
seg)
> * Big batch jobs should use one big RBS
> * ORA-600 means you have corruption / just call support for ORA-600
> * Lots of extents are bad
> * Databases can't be renamed
> * Select count (1) is better than count (*).
> * Listeners have to be started before the instance
> * NOLOGGING turns off logging for all operations
> * Oracle Corp. won't support NFS datafiles
> * checkpoint not complete - misguided solutions
> * Must reinstantiate standby after failover by recopying
> * redolog size change requires outage
>
> What's *your* pet misconception?
>
> --
> Jeremiah Wilton
> http://www.speakeasy.net/~jwilton
>
> On Tue, 26 Jun 2001, novicedba wrote:
>
> > I visited Jeremiah Wilton's web page http://www.speakeasy.net/~jwilton
> > I was shocked to read Hot backup mode explained
> > If this is true then I may be a victim of a disease called
> > 'Common Oracle RDBMS Misconceptions' . Somebody help me!! (Jim
carrey-MASK style)
> > Please help me. If some one has few more articles like this enlighten me
>
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.com
> --
> Author: Jeremiah Wilton
> INET: jwilton_at_speakeasy.net
>
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-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Terry Ball
  INET: terry_ball_at_csgsystems.com

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-- 
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-- 
Author: Toepke, Kevin M
  INET: ktoepke_at_cms.cendant.com

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San Diego, California        -- Public Internet access / Mailing Lists
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