i thought full scan does 1 block at a time and fast full scan does your multiblock_read_count? > > From: Mladen Gogala <[EMAIL PROTECTED]> > Date: 2003/10/23 Thu PM 11:34:25 EDT > To: Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]> > Subject: Re: index full scan over an index fast full scan in an analytic function? > > B*tree indexes are ALWAY ordered. That's the way they're created and searched. > I don't know the difference between full index scan and fast full index scan. > I know that the latter is used when the tble rows are not needed. Sounds like > both methods are reading all leaf blocks, from start to finish, using > multiblock read. I am not aware of any difference between the two methods. > This sounds like a question for asktom or ixora (Tom Kyte or Steve Adams). > Wolfgang Breitling and J. Lewis might also know. > > On 2003.10.23 23:14, Larry Elkins wrote: > > Because when doing an index range scan things are read ordered? Very > > different from an index fast full scan where blocks are simply grabbed where > > they might lie? > > > > Regards, > > > > Larry G. Elkins > > The Elkins Organization Inc. > > [EMAIL PROTECTED] > > 214.954.1781 > > > > > -----Original Message----- > > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of > > > Ryan > > > Sent: Thursday, October 23, 2003 9:34 PM > > > To: Multiple recipients of list ORACLE-L > > > Subject: Re: index full scan over an index fast full scan in an analytic > > > function? > > > > > > > > > why would you not need a sort with a full index scan and need one with a > > > fast full scan? > > > ----- Original Message ----- > > > To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> > > > Sent: Thursday, October 23, 2003 5:19 PM > > > function? > > > > > > > > > > Possibly to avoid a sort operation (assuming that you might be > > > able to get > > > > away with a NOSORT when doing the full index scan)? It might be deciding > > > > that the benefit of the multi-block reads for the fast full > > > scan are more > > > > than offset by the sort operation that would be needed (and might not be > > > > needed when doing the full index scan). > > > > > > > > Regards, > > > > > > > > Larry G. Elkins > > > > The Elkins Organization Inc. > > > > [EMAIL PROTECTED] > > > > 214.954.1781 > > > > > > > > > -----Original Message----- > > > > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of > > > > > [EMAIL PROTECTED] > > > > > Sent: Thursday, October 23, 2003 2:39 PM > > > > > To: Multiple recipients of list ORACLE-L > > > > > Subject: Re: index full scan over an index fast full scan in > > > an analytic > > > > > function? > > > > > > > > > > > > > > > i cant attach the 10053 trace. it has proprietary info. There > > > > > isnt much in analytic explain plan either. > > > > > > > > > > does anyone know in general why a full scan would be faster than > > > > > a fast full scan? > > > > > > > > > > > > From: <[EMAIL PROTECTED]> > > > > > > Date: 2003/10/23 Thu PM 03:09:26 EDT > > > > > > To: Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]> > > > > > > Subject: index full scan over an index fast full scan in an > > > > > analytic function? > > > > > > > > > > > > I have an index on the two columns used in this query. Why > > > > > would the optimizer choose an index full scan over an index fast > > > > > full scan? > > > > > > > > > > > > My question isnt why an index is used, but the type of index scan? > > > > > > > > > > > > select * > > > > > > from (select col1, col2, > > > > > > dense_rank() > > > > > > over (partition by col1 > > > > > > order by col2 desc)tab > > > > > > from mytable) > > > > > > where tab = 1 > > > > > > > > > > > > -- > > > > > > Please see the official ORACLE-L FAQ: http://www.orafaq.net > > > > > > -- > > > > > > Author: <[EMAIL PROTECTED] > > > > > > INET: [EMAIL PROTECTED] > > > > > > > > > > > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > > > > > > San Diego, California -- Mailing list and web > > > hosting services > > > > > > > > > --------------------------------------------------------------------- > > > > > > To REMOVE yourself from this mailing list, send an E-Mail message > > > > > > to: [EMAIL PROTECTED] (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.net > > > > > -- > > > > > Author: <[EMAIL PROTECTED] > > > > > INET: [EMAIL PROTECTED] > > > > > > > > > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > > > > > San Diego, California -- Mailing list and web hosting services > > > > > --------------------------------------------------------------------- > > > > > To REMOVE yourself from this mailing list, send an E-Mail message > > > > > to: [EMAIL PROTECTED] (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.net > > > > -- > > > > Author: Larry Elkins > > > > INET: [EMAIL PROTECTED] > > > > > > > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > > > > San Diego, California -- Mailing list and web hosting services > > > > --------------------------------------------------------------------- > > > > To REMOVE yourself from this mailing list, send an E-Mail message > > > > to: [EMAIL PROTECTED] (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.net > > > -- > > > Author: Ryan > > > INET: [EMAIL PROTECTED] > > > > > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > > > San Diego, California -- Mailing list and web hosting services > > > --------------------------------------------------------------------- > > > To REMOVE yourself from this mailing list, send an E-Mail message > > > to: [EMAIL PROTECTED] (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.net > > -- > > Author: Larry Elkins > > INET: [EMAIL PROTECTED] > > > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > > San Diego, California -- Mailing list and web hosting services > > --------------------------------------------------------------------- > > To REMOVE yourself from this mailing list, send an E-Mail message > > to: [EMAIL PROTECTED] (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). > > > > -- > Mladen Gogala > Oracle DBA > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: Mladen Gogala > INET: [EMAIL PROTECTED] > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > San Diego, California -- Mailing list and web hosting services > --------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (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.net -- Author: <[EMAIL PROTECTED] INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (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).
