Return-Path: Received: from newsfeed.cts.com (newsfeed.cts.com [209.68.248.164]) by naude.co.za (8.11.2/8.11.2) with SMTP id g2DJPGn32489 for ; Wed, 13 Mar 2002 14:25:16 -0500 Received: from fatcity.UUCP (uucp@localhost) by newsfeed.cts.com (8.9.3/8.9.3) with UUCP id LAA11083; Wed, 13 Mar 2002 11:10:36 -0800 (PST) Received: by fatcity.com (26-Feb-2001/v1.0g-b70/bab) via UUCP id 00427830; Wed, 13 Mar 2002 09:53:29 -0800 Message-ID: Date: Wed, 13 Mar 2002 09:53:29 -0800 To: Multiple recipients of list ORACLE-L X-Comment: Oracle RDBMS Community Forum X-Sender: "Jonathan Lewis" Sender: root@fatcity.com Reply-To: ORACLE-L@fatcity.com Errors-To: ML-ERRORS@fatcity.com From: "Jonathan Lewis" Subject: Re: Fav. Urban Legend... Organization: Fat City Network Services, San Diego, California X-ListServer: v1.0g, build 70; ListGuru (c) 1996-2001 Bruce A. Bergman Precedence: bulk Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit How about - Oracle's decision to use an index for a query is determined by the percentage of rows from the table identified by the index. Hints are only suggestions and Oracle is allowed to ignore them Jonathan Lewis http://www.jlcomp.demon.co.uk Next Seminar - UK, April 3rd - 5th http://www.jlcomp.demon.co.uk/seminar.html Host to The Co-Operative Oracle Users' FAQ http://www.jlcomp.demon.co.uk/faq/ind_faq.html Author of: Practical Oracle 8i: Building Efficient Databases -----Original Message----- To: Multiple recipients of list ORACLE-L Date: 13 March 2002 17:02 |Yep, had that one... another of my fav's! | |Robert G. Freeman - Oracle8i OCP |Oracle DBA Technical Lead |CSX Midtier Database Administration | |The Cigarette Smoking Man: Anyone who can appease a man's conscience can |take his freedom away from him. | | | |-----Original Message----- |Sent: Wednesday, March 13, 2002 8:28 AM |To: Multiple recipients of list ORACLE-L | | |And the time honoured favourite... | |"All performance problems can be resolved by |modification of init.ora parameters, in particular, |any parameter that starts with an underscore" | | --- Jonathan Lewis |wrote: > |> My next to favourite legends. |> |> Small tables don't need to be indexed |> |> Small tables are anything 4 blocks or less |> |> Oracle copies the entire row into the rollback |> segment when updating a single column. |> |> Oracle copies the entire block into the rollback |> segment when updating a row. |> |> Oracle can only use 5 indexes in a query |> (though I haven't heard that one much |> recently) |> |> Setting tablespace default pctincrease to 1 |> reduces |> fragmentation problems. |> (but that's going out of fashion too) |> |> But I guess you, Jeremiah and Rachel have |> already got those covered. |> |> |> |> Jonathan Lewis |> http://www.jlcomp.demon.co.uk |> |> Next Seminar - UK, April 3rd - 5th |> http://www.jlcomp.demon.co.uk/seminar.html |> |> Host to The Co-Operative Oracle Users' FAQ |> http://www.jlcomp.demon.co.uk/faq/ind_faq.html |> |> Author of: |> Practical Oracle 8i: Building Efficient Databases |> |> |> -----Original Message----- |> To: Multiple recipients of list ORACLE-L |> |> Date: 12 March 2002 22:54 |> |> |> |Everyone, some great ideas.... |> | |> |RF |> | |> |Robert G. Freeman - Oracle8i OCP |> |Oracle DBA Technical Lead |> |CSX Midtier Database Administration |> |> |> -- |> Please see the official ORACLE-L FAQ: |> http://www.orafaq.com |> -- |> Author: Jonathan Lewis |> INET: jonathan@jlcomp.demon.co.uk |> |> Fat City Network Services -- (858) 538-5051 FAX: |> (858) 538-5051 |> San Diego, California -- Public Internet |> access / Mailing Lists |> |-------------------------------------------------------------------- |> To REMOVE yourself from this mailing list, send an |> E-Mail message |> to: ListGuru@fatcity.com (note EXACT spelling of |> 'ListGuru') and in |> the message BODY, include a line containing: UNSUB |> ORACLE-L |> (or the name of mailing list you want to be removed |> from). You may |> also send the HELP command for other information |> (like subscribing). | |===== |Connor McDonald |http://www.oracledba.co.uk (mirrored at |http://www.oradba.freeserve.co.uk) | |"Some days you're the pigeon, some days you're the statue" | |__________________________________________________ |Do You Yahoo!? |Everything you'll ever need on one web page |from News and Sport to Email and Music Charts |http://uk.my.yahoo.com |-- |Please see the official ORACLE-L FAQ: http://www.orafaq.com |-- |Author: =?iso-8859-1?q?Connor=20McDonald?= | INET: hamcdc@yahoo.co.uk | |Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 |San Diego, California -- Public Internet access / Mailing Lists |-------------------------------------------------------------------- |To REMOVE yourself from this mailing list, send an E-Mail message |to: ListGuru@fatcity.com (note EXACT spelling of 'ListGuru') and in |the message BODY, include a line containing: UNSUB ORACLE-L |(or the name of mailing list you want to be removed from). You may |also send the HELP command for other information (like subscribing). |-- |Please see the official ORACLE-L FAQ: http://www.orafaq.com |-- |Author: Freeman, Robert | INET: Robert_Freeman@csx.com | |Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 |San Diego, California -- Public Internet access / Mailing Lists |-------------------------------------------------------------------- |To REMOVE yourself from this mailing list, send an E-Mail message |to: ListGuru@fatcity.com (note EXACT spelling of 'ListGuru') and in |the message BODY, include a line containing: UNSUB ORACLE-L |(or the name of mailing list you want to be removed from). You may |also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jonathan Lewis INET: jonathan@jlcomp.demon.co.uk Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru@fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).