Kevin, Have you analyzed the tables on both databases? Card is the CBO's estimate of the number of rows it will process.
Mike >From: "kevin wang" <[EMAIL PROTECTED]> >Reply-To: [EMAIL PROTECTED] >To: Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]> >Subject: question on EXPLAIN_PLAN >Date: Wed, 06 Feb 2002 11:43:38 -0800 > > Hi, guys > > The problem belows is really make me confused and gave me big trouble, >is there someone can give me some hlep? > > I have two databses, same version(oracle 8.1.6),same O/S(win2000), same >schema structure, different data(but small difference of size). > and even exactly same explain_plan of my sql query. > But on one database, the cardinality of one PK index access upon one >table is 27(cost=2,card=27,bytes=756) (table rows 263758) > and the other is 11706!!!! (cost=3,card=11706,bytes=199002)( table rows >351173). > so, on one DB the sql query took 300ms, one the other, it took 5 >seconds! > > Any advise is highly appreciated. > > thanks, > > Kevin Wang > Database Administrator > Vivonet Canada Inc. > > > _________________________________________________________________ Chat with friends online, try MSN Messenger: http://messenger.msn.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Mike Killough INET: [EMAIL PROTECTED] 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: [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).
