Re: RE: performance when inserting into child tables

hi,Mercadante, Thomas F

 exec dbms_system.set_ev(sid,serial#,10046,8,'')      ;
 trace the  insert . 

plz notice that , how  many users do the inserting , which=
 version for the  oracle ,which tablespace ? LMT/ASSM  ?
if  LMT and more than one user , freelists ?   

if the child table  has no index , the parent table changing may=
 lock the child table 




Best regards

yahoo id: feng_chunpei
A new dba from china

---- from the  mail-----
>No - haven't tested it.  I guess I wouldn't want to go changing=
 my
>production system just on an Oracle class say-so.
>
>How would you test it?  If it takes a lock and "quickly"=
 releases it, can we
>see how long the lock was held for?
>
>Tom Mercadante
>Oracle Certified Professional
>
>
>-----Original Message-----
>From: Jared.Still@xxxxxxxxxxx [mailto:Jared.Still@xxxxxxxxxxx]
>Sent: Wednesday, April 21, 2004 2:38 PM
>To: oracle-l@xxxxxxxxxxxxx
>Subject: RE: performance when inserting into child tables
>
>
>"The lack of indexes for the FK's will cause a share lock to be=
 taken 
>out on the child table when ever the parent is deleted or=
 updated."
>The most recent Oracle class I took said that in 9i, this lock=
 on the 
>child
>table is taken and released immediately.  Supposedly to speed=
 the process 
>up
>a bit.
>
>-----
>
>I did consider that this might have changed in 9i.
>
>The posted didn't mention a version, so I didn't pursue it.
>
>Have you tested to see if this is what happens in 9i?
>
>Jared
>
>
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>.


=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1



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