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 > > >----------------------------------------------------------------= >Please see the official ORACLE-L FAQ: http://www.orafaq.com >----------------------------------------------------------------= >To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx >put 'unsubscribe' in the subject line. >-- >Archives are at //www.freelists.org/archives/oracle-l/ >FAQ is at //www.freelists.org/help/fom-serve/cache/1.html >----------------------------------------------------------------= - >----------------------------------------------------------------= >Please see the official ORACLE-L FAQ: http://www.orafaq.com >----------------------------------------------------------------= >To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx >put 'unsubscribe' in the subject line. >-- >Archives are at //www.freelists.org/archives/oracle-l/ >FAQ is at //www.freelists.org/help/fom-serve/cache/1.html >----------------------------------------------------------------= - > >. =A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1 ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx put 'unsubscribe' in the subject line. -- Archives are at //www.freelists.org/archives/oracle-l/ FAQ is at //www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------