Re: _optimizer_undo_changes

Jeff,

To get the current values and a skimpy explanantion of the undocumented = parameters, also query the x$ksppcv table.

As SYS
SQL> select ksppinm, ksppstvl, ksppdesc

           from x$ksppi x, x$ksppcv y
           where x.indx = y.indx and
           translate(ksppinm,'_','#') like '#%';

Regards,
Craig M. Wall

    Jeffrey Hunter wrote in message <35A39417.80553938_at_fore.com>...     In short, what does the hidden parameter:     _optimizer_undo_changes do? We are about ready to     set this parameter to TRUE in our ERP database as     per the request of Oracle but don't know if we will     see any performance issues with this change.     Also, how do we find out the value of a hidden variable?     For normal parameters, we look at v$parameter. I know     that if you want to get a listing of all hidden parameters     you can query X$KSPPI:

    SELECT KSPPINM
    FROM X$KSPPI
    WHERE SUBSTR (KSPPINM, 1, 1) = '_';     How do I find out what the current value of     _optimizer_undo_changes is set to? (TRUE || FALSE)?

    Any pointers would be greatly appreciated!

• jeff

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