Optimizer Parameter

1. Cost Model 변경

alter session set "_optimizer_cost_model" = io;

alter session set "_optimizer_cost_model" = cpu;

alter session set "_optimizer_cost_model" = choose;

2. dbf 파일을 먼저 삭제하고 startup 하였을때 .

 - ORA-01157: cannot identify/lock data file 10 - see DBWR trace file

alter database datafile '/hdd/dbf/test1.dbf' offline drop;

3. tablespace 정보 확인

select FILE_NAME, TABLESPACE_NAME,BYTES,MAXBYTES from dba_data_files;

select FILE_NAME,TABLESPACE_NAME from dba_data_files;