AK, I'd still do some testing with a bitmap index on that column. You have 1,000,000 records. 500 records have value in that column. That means the absolute most distinct values in that column is 501. This is at least one criteria for bitmap candidacy. What I see in testing is select * from table where A = 'some value' can use the bitmap index. Also I see select * from table where A is null also uses the bitmap index. I'm definitely not saying this as 'end all', just saying it might be worth playing with.
Darrell Landrum Database Administrator Zale Corporation >>> [EMAIL PROTECTED] 03/28/03 09:59AM >>> It means if I do a query with where clause with A=:x its going to go for index . Does oracle go to table if :x is null. It looks like it does . ??? -ak ----- Original Message ----- To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: Thursday, March 27, 2003 6:33 PM > AK > Yes, it will benefit the non-null records. Just remember that the null > values aren't indexes. > > > > Dennis Williams > DBA, 40%OCP, 100% DBA > Lifetouch, Inc. > [EMAIL PROTECTED] > > -----Original Message----- > Sent: Thursday, March 27, 2003 5:19 PM > To: Multiple recipients of list ORACLE-L > > > I have a table with column A. there are 1000000 records in table out of > which 500o records has not null in column A rest are null. > if i created an index on A, will it benefit . > > thanks, > ak > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: DENNIS WILLIAMS > 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: AK 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: Darrell Landrum 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).
