>Compute Statistics

>table için;
begin
dbms_stats.gather_table_stats(ownname=> ‘SAPSR3’, tabname=> ‘MARG’, partname=> NULL);
end;

tablespace için;
begin
dbms_stats.gather_schema_stats(ownname=> ‘SAPSR3’ , cascade=> TRUE);
end;

http://blog.csdn.net/guozhenblog/category/260868.aspx