Unlike the document, many other optimizer parameters are controlled by OPT_PARAM hint. My assumption: OPT_PARAM might work in the query block level as many other hints. So some parameters which should be applied at the statement level(like optimizer_features_enable) would not work with OPT_PARAM hint. It would be by design, not mistake by developers. ================================ Dion Cho - Oracle Performance Storyteller http://dioncho.wordpress.com (english) http://ukja.tistory.com (korean) http://dioncho.blogspot.com (japanese) http://ask.ex-em.com (q&a) ================================ 2009/11/24 hrishy <hrishys@xxxxxxxxxxx> > Hi > > > The opt_parm hint is valid > OPTIMIZER_DYNAMIC_SAMPLING, > OPTIMIZER_INDEX_CACHING, > OPTIMIZER_INDEX_COST_ADJ, > OPTIMIZER_SECURE_VIEW_MERGING, and > STAR_TRANSFORMATION_ENABLED > > hence your hint is silently ignored as it is inavlid. > > You might want to try > alter session set "optimizer_features_enable"= '9.2.0'; > > > > > --- On *Tue, 24/11/09, LS Cheng <exriscer@xxxxxxxxx>* wrote: > > > From: LS Cheng <exriscer@xxxxxxxxx> > Subject: OPT_PARAM > To: "Oracle Mailinglist" <oracle-l@xxxxxxxxxxxxx> > Date: Tuesday, 24 November, 2009, 7:14 > > Hi > > Does anyone know if opt_param hint works with optimizer_features_enable in > 11.1.0.7? > > I am testing it and it seems that it gets ignored > > enable event 10132 > > SELECT > /*+ opt_param('optimizer_features_enable', '9.2.0') */ > x, y, z > FROM v_lsc > WHERE x = 'S' OR y_date > to_date(:V1, 'MM/DD/YY HH24:MI:SS'); > > Content of other_xml column > =========================== > db_version : 11.1.0.7 > parse_schema : SIMO > plan_hash : 2064770634 > plan_hash_2 : 1803173905 > Peeked Binds > ============ > Bind variable information > position=1 > datatype(code)=1 > datatype(string)=VARCHAR2(32) > char set id=31 > char format=1 > max length=32 > value=11/20/09 14:01:27 > Outline Data: > /*+ > BEGIN_OUTLINE_DATA > IGNORE_OPTIM_EMBEDDED_HINTS > * OPTIMIZER_FEATURES_ENABLE('9.2.0')* > .............. > Optimizer state dump: > .............. > *optimizer_features_enable = 11.1.0.7* > > > Although in outline section it sees 9.2.0 optimizer afterwards it still > uses 11.1.0.7 > > > Thanks > > > > > > > >