Path: dp-news.maxwell.syr.edu!spool.maxwell.syr.edu!drn.maxwell.syr.edu!news.maxwell.syr.edu!news-rtr.nyroc.rr.com!news-out.nyroc.rr.com!twister.nyroc.rr.com.POSTED!53ab2750!not-for-mail Reply-To: "Anurag Varma" From: "Anurag Varma" Newsgroups: comp.databases.oracle.server References: <1107294624.883089.138330@f14g2000cwb.googlegroups.com> <6uvvv0l4bvruln8rhk9l15vf4kk7m7g40r@4ax.com> <1107297368.557772.11400@c13g2000cwb.googlegroups.com> Subject: Re: index fast full scan - why so slow and expensive Lines: 34 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2800.1437 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1441 Message-ID: <05_Ld.17495$8H2.16018@twister.nyroc.rr.com> Date: Wed, 02 Feb 2005 06:05:48 GMT NNTP-Posting-Host: 66.66.3.212 X-Complaints-To: abuse@rr.com X-Trace: twister.nyroc.rr.com 1107324348 66.66.3.212 (Wed, 02 Feb 2005 01:05:48 EST) NNTP-Posting-Date: Wed, 02 Feb 2005 01:05:48 EST Organization: Road Runner Xref: dp-news.maxwell.syr.edu comp.databases.oracle.server:234777 "Sybrand Bakker" wrote in message news:h9p001dloosmvs7i5qdacl2v6i327lfesc@4ax.com... -snip- > - The INDEX hint will use the normal access methods. However it is a > *hint*. As you are deliberately vague about the actual statement, it's > explain plan etc, and you obviously didn't run explain plan with event > 10053 set, it is impossible to tell why Oracle choose the index_ffs > method > > - I hardly use it, you will need to very that in the docs > > - If the clustering factor approximates the number of records it is > good (recalling from memory), it is approximates the number of blocks > it is bad. opposite. If CF nears number of table blocks .. its good If CF nears the number of table records .. its bad. > You would need to rebuild the table and make sure the records are > loaded in the correct order. Obviously, if your table is a heap table, > you would need to repeat this periodically. > > > -- > Sybrand Bakker, Senior Oracle DBA To OP ... have a look at www.dizwell.com -> DBA Tips -> Tuning -> The clustering factor ... for an excellent writeup of clustering factor by Howard. Anurag