Hi, Chris! CBO will only choose a INDEX SKIP SCAN if that access path has a lower cost than other alternatives. CBO calcluates the cost for a ISS to be: BLEVEL + #of distinct values of skipped column(s). Cheers / Jocke Treugut www.treugut-tuning.com Höstrusk och grå moln - köp en resa till solen på Yahoo! Resor på adressen http://se.docs.yahoo.com/travel/index.html ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx put 'unsubscribe' in the subject line. -- Archives are at //www.freelists.org/archives/oracle-l/ FAQ is at //www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------