On index-obsessed apps, you'll often see massive
amount of LIO to a target of a nested loop.  ie, scan
mega table and then index probe the inner table for
every row of the mega table...

Generally you'll see smoke coming out of the index
root/branch blocks on the target table :-)

hth
connor

 --- Greg Moore <[EMAIL PROTECTED]> wrote: > A while
back someone mentioned that the two main
> causes of slow SQL are
> excesive LIO's and excesscive database calls, which
> show up as excessive CPU
> use and excessive network traffic, respectively.
> 
> Regarding the database calls, is there a "classic"
> reason for this problem?
> 
> My best guess is it's caused by an SQL statement in
> a PL/SQL loop, which
> could be rewritten as a single SQL statement.  But
> is this the single,
> commonly seen cause for this problem, or are there
> other common ways this
> inefficiency is introduced?
> 
> Thanks in advance for help in understanding this.
> 
> -- 
> Please see the official ORACLE-L FAQ:
> http://www.orafaq.com
> -- 
> Author: Greg Moore
>   INET: [EMAIL PROTECTED]
> 
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=====
Connor McDonald
http://www.oracledba.co.uk
http://www.oaktable.net

"GIVE a man a fish and he will eat for a day. But TEACH him how to fish, and...he will 
sit in a boat and drink beer all day"

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