Chris, If you try SQLTXPLAIN (SQLT) MOS 215187.1 please use SQLT XTRACT in both and send me output zip files. I can do a quick review. Or you can also use SQLT COMPARE from both. There are so many things to compare manually. An automated mechanism reduces the human effort and error. Cheers -- Carlos On Wed, Apr 25, 2012 at 1:34 PM, Taylor, Chris David < ChrisDavid.Taylor@xxxxxxxxxxxxxxx> wrote: > Oracle will often favor a full tablescan when the data you want is spread > out across multiple Oracle blocks - so say the table only has 50 Oracle > blocks, and your data occupies 45 of them then it's 'cheaper' to do a FTS > since it has to read most of the Oracle blocks anyway. > > That's the point I was trying to find floating around in my head... > > > Chris > > -----Original Message----- > From: Taylor, Chris David > Sent: Wednesday, April 25, 2012 12:09 PM > To: 'Li Li' > Cc: 'oracle-l@xxxxxxxxxxxxx' > Subject: RE: query uses function based index in DEV1 db but does NOT use > it in DEV2 db > > <snip> > There are times where if you've asked for some percentage of a table's > rows, but because that percentage is spread out across the whole table, > that Oracle will favor a FTS even when asked for a small percentage of the > table's rows. (I was trying to find an example of this but can't put my > fingers on it at the moment...) > </snip> > > -- > //www.freelists.org/webpage/oracle-l > > > -- //www.freelists.org/webpage/oracle-l