Path: text.usenetserver.com!out01a.usenetserver.com!news.usenetserver.com!in02.usenetserver.com!news.usenetserver.com!postnews.google.com!news3.google.com!border1.nntp.dca.giganews.com!nntp.giganews.com!local01.nntp.dca.giganews.com!nntp.bt.com!news.bt.com.POSTED!not-for-mail NNTP-Posting-Date: Tue, 12 Dec 2006 16:35:02 -0600 From: "Jonathan Lewis" Newsgroups: comp.databases.oracle.server References: <1165960064.046563.211800@n67g2000cwd.googlegroups.com> <1165961761.805346.111320@16g2000cwy.googlegroups.com> <1165962649.719151.162500@16g2000cwy.googlegroups.com> Subject: Re: Join selectivity is 0 causing bad cardinality estimates. Date: Tue, 12 Dec 2006 22:35:03 -0000 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2900.2869 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2962 X-RFC2646: Format=Flowed; Original Message-ID: <0_idnbY-AosLs-LYnZ2dnUVZ8ty3nZ2d@bt.com> Lines: 27 NNTP-Posting-Host: 86.130.242.224 X-AuthenticatedUsername: NoAuthUser X-Trace: sv3-vU4u6zStPQEQ8RYz9IXouaR/acaOLDknB1y7yTWTi+PNbnk4nGm3fc2tJ52iuiBemrOKg8jzoemeyGb!N1wCecnQoEiBpPnUm2w7DW61j9g/L9MtLNYf4mvFYhKnRSQBy8wT63V3Rh6EeDiOeOIA7HW3+nGh X-Complaints-To: abuse@btinternet.com X-DMCA-Complaints-To: abuse@btinternet.com X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.32 Xref: usenetserver.com comp.databases.oracle.server:419075 X-Received-Date: Tue, 12 Dec 2006 17:35:03 EST (text.usenetserver.com) wrote in message news:1165962649.719151.162500@16g2000cwy.googlegroups.com... > We also have histograms calculated using a similar method as you have, > FOR ALL COLUMNS SIZE AUTO. > That's your main problem. You don't need histograms on all columns, and you don't want to let Oracle work out the details. -- Regards Jonathan Lewis http://jonathanlewis.wordpress.com Author: Cost Based Oracle: Fundamentals http://www.jlcomp.demon.co.uk/cbo_book/ind_book.html The Co-operative Oracle Users' FAQ http://www.jlcomp.demon.co.uk/faq/ind_faq.html