Well, I know for a fact that this is the case in 10g as it happened to me just the other day. I had a situation where a.x=b.x and a.x in ('a','b','c',.... etc.) and the optimizer choose to use an index on b.x Ken -----Original Message----- From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Allen, Brandon Sent: Thursday, October 19, 2006 11:50 AM To: paul.baumgartel@xxxxxxxxxxxxxxxxx; breitliw@xxxxxxxxxxxxx; Jacques.Kilchoer@xxxxxxxxx Cc: oracle-l Subject: RE: should one use ANSI join syntax when writing an Oracle applic ation? I thought Oracle was smart enough to perform transitive closure on its own even if you don't explicitly write it in your SQL, e.g. Metalink #68979.1: "Transitivity and Transitive Closure =================================== Purpose ~~~~~~~ This article explains how the Cost Based Optimizer (CBO) generates transitive predicates to open potential new access methods." > -----Original Message----- > From: oracle-l-bounce@xxxxxxxxxxxxx > [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Baumgartel, Paul > Wolfgang, > > Just to confirm, your point is that adding > the (logically unnecessary) "and A.x = C.x" provides more > information that the optimizer can use to choose a more > efficient access path? > > > > -----Original Message----- > From: oracle-l-bounce@xxxxxxxxxxxxx > [mailto:oracle-l-bounce@xxxxxxxxxxxxx]On Behalf Of Wolfgang Breitling > > I need some help here. How do I code a full transitive > closure join with the new syntax? In the traditional syntax I can say: > Privileged/Confidential Information may be contained in this message or attachments hereto. Please advise immediately if you or your employer do not consent to Internet email for messages of this kind. Opinions, conclusions and other information in this message that do not relate to the official business of this company shall be understood as neither given nor endorsed by it. -- //www.freelists.org/webpage/oracle-l -- //www.freelists.org/webpage/oracle-l