Update Statistics - Cost of using a Function as an Index...

Hi, I executed some tests here with function as an index. 1) I created an index , using a function: create index ix_dt on tst1 (dt_periodo(hora)); 2) Ran update statistics on the column where the function was applied : update statistics low for table tst1(hora); 3) Then I executed the query using this function... the optimizer used the index but the costs have changed just a little... select * , dt_periodo(hora) periodo from tst1 where dt_periodo(hora) = "tarde" 4) Ran an update statistics on the table without specified any column: update statistics low for table tst1; 5) Finally I re-executed the query using this function... this time the costs went down considerably... I looked up on manuals but didn't find any information on how I could execute an update statistics only for this index. Does anybody know if this is possible or if I have to execute an update statistics on all columns of the table?? ____________________________________________________________________________________ Novo Yahoo! Cadê? - Experimente uma nova busca. http://yahoo.com.br/oqueeuganhocomisso