Could you confirm what you mean by: "activated only one node". a) You didn't start the second instance, and leave it to the cluster manager to fail over the package and start the second instance if the first instance fails b) You changed the tnsnames.ora so that all connections went to the first instance, and did nothing else (load_balance = off) (failover = on) c) You restarted both instances after setting the 'active_instance_count' to 1, so that RAC would start up in a proper primary/secondary state - with the entire global resource directory held on the primary node ? (And adjusted tnsnames.ora accordingly). Regards Jonathan Lewis http://www.jlcomp.demon.co.uk/faq/ind_faq.html The Co-operative Oracle Users' FAQ http://www.jlcomp.demon.co.uk/seminar.html Optimising Oracle Seminar - schedule updated Sept 19th ---- from the mail----- >Hi All, > >I has oracle9i database with RAC using 2 nodes. >The first time i used them, i activated server load >balancing, so user connect to least loaded instance. > >But after i checked 'gcs/ges wait' related to cache >fusion, that is very large, i activate only one node, >and use another node as failover node. >What i expected here was, i want to reduce >intercluster operations for sql/dml. > >The problem i still got was, when one table was >actively update by many users and i did full table >scan on it, it's quite slow. I have compared it with >non-RAC database, it's about 2-3 times slower. >I have activated sql trace, and found many2 of 'global >cr request' wait on that full table scan. > -- //www.freelists.org/webpage/oracle-l