Path: news.easynews.com!easynews!news.he.net!cyclone-sf.pbi.net!64.245.249.51!sfo2-feed1.news.algx.net!allegiance!news2.euro.net!newsfeed.stueberl.de!teaser.fr!deine.net!intgwpad.nntp.telstra.net!news.telstra.net!newsfeeds.bigpond.com!not-for-mail From: "Richard Foote" Newsgroups: comp.databases.oracle.server References: Subject: Re: CHOOSE & RULE Lines: 32 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Message-ID: Date: Thu, 6 Jun 2002 18:45:18 +1000 NNTP-Posting-Host: 144.134.117.251 X-Trace: newsfeeds.bigpond.com 1023353542 144.134.117.251 (Thu, 06 Jun 2002 18:52:22 EST) NNTP-Posting-Date: Thu, 06 Jun 2002 18:52:22 EST Organization: Telstra BigPond Internet Services (http://www.bigpond.com) Xref: easynews comp.databases.oracle.server:149714 X-Received-Date: Thu, 06 Jun 2002 03:55:29 MST (news.easynews.com) The question lacks specific details (such as the SQL in question, database version, etc.) so unfortunately so will this answer. Basically, without the hint, the statement is using the cost based optimizer and its execution plan is obviously not as desirable as the execution plan derived by the rule based optimizer. Reasons for this are too numerous to mention... You need to "explain" the statements (let me know if you don't know how to do this) and compare the two execution plans. The answer will then be set out before you. Swap more information for more information if required. Richard "Oraclion" wrote in message news:adn50p$ac7$1@wanadoo.fr... > Hi > > Note: Optimiser is set to CHOOSE > > My request is very speed with a RULE hint in the request but if i dont't use > the hint it's very very slowly !!! > Why ? > > Thanks > Oraclion > >