Comments on: select last rows http://laurentschneider.com/wordpress/2006/08/select-last-rows.html Oracle Certified Master Fri, 09 Jan 2009 00:41:39 +0000 http://wordpress.org/?v=2.6.5 By: Laurent Schneider http://laurentschneider.com/wordpress/2006/08/select-last-rows.html#comment-6533 Laurent Schneider Thu, 01 May 2008 20:00:14 +0000 http://laurentschneider.com/wordpress/2006/08/04/select-last-rows/#comment-6533 there is not ALTER TABLE, you need to create a new table, with online redefinition if you want there is not ALTER TABLE, you need to create a new table, with online redefinition if you want

]]> By: Simon Hunt http://laurentschneider.com/wordpress/2006/08/select-last-rows.html#comment-6527 Simon Hunt Thu, 01 May 2008 17:59:26 +0000 http://laurentschneider.com/wordpress/2006/08/04/select-last-rows/#comment-6527 Hi Laurent, I am trying to implement ORA_ROWSCN to control the optimistic locking on my app. Is it possible to enable row dependencies on an existing table? or will I need to do an online rebuild? Simon Hi Laurent,

I am trying to implement ORA_ROWSCN to control the optimistic locking on my app. Is it possible to enable row dependencies on an existing table? or will I need to do an online rebuild?

Simon

]]> By: Laurent Schneider http://laurentschneider.com/wordpress/2006/08/select-last-rows.html#comment-283 Laurent Schneider Fri, 04 Aug 2006 23:14:00 +0000 http://laurentschneider.com/wordpress/2006/08/04/select-last-rows/#comment-283 yes, thanks, and also not for uncommited rows if the table has rowdependencies! SCOTT@LSC01> update t set x=0 where rownum=1; 1 row updated. SCOTT@LSC01> select ora_rowscn from t where x=0; ORA_ROWSCN ---------- yes, thanks, and also not for uncommited rows if the table has rowdependencies!

SCOTT@LSC01> update t set x=0 where rownum=1;

1 row updated.

SCOTT@LSC01> select ora_rowscn from t where x=0;
ORA_ROWSCN
———-

]]> By: Thomas Kyte http://laurentschneider.com/wordpress/2006/08/select-last-rows.html#comment-282 Thomas Kyte Fri, 04 Aug 2006 23:05:00 +0000 http://laurentschneider.com/wordpress/2006/08/04/select-last-rows/#comment-282 also, it only works for rows updated relatively recently sys%ORA10GR2> select min(ora_rowscn) from obj$; MIN(ORA_ROWSCN) --------------- 18349 sys%ORA10GR2> select scn_to_timestamp(18349) from dual; select scn_to_timestamp(18349) from dual * ERROR at line 1: ORA-08181: specified number is not a valid system change number ORA-06512: at "SYS.SCN_TO_TIMESTAMP", line 1 also, it only works for rows updated relatively recently

sys%ORA10GR2> select min(ora_rowscn) from obj$;

MIN(ORA_ROWSCN)
—————
18349

sys%ORA10GR2> select scn_to_timestamp(18349) from dual;
select scn_to_timestamp(18349) from dual
*
ERROR at line 1:
ORA-08181: specified number is not a valid system change number
ORA-06512: at “SYS.SCN_TO_TIMESTAMP”, line 1

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