Oracle FAQs and Tips
2024-08-29 13:45:38
供稿：網友
在已建好的table上添加PRimary key
1.建立索引
create index test_idx
on test(id);
2.添加約束
alter table test
add constraint test_pk primary key (id)
using index test_idx; 在SQLPLUS中登陸時出現以下錯誤
ERROR:
ORA-12638: Credential retrieval failed
解決方法:修改sqlnet.ora
假如SQLNET.AUTHENTICATION_SERVICES= (NTS)一行沒有被注釋,則注釋掉
#SQLNET.AUTHENTICATION_SERVICES= (NTS)
反之取消注釋ALTER SYSTEM SET EVENTS='10231 trace name context forever,level 10' ;
內部事件，設置在全表掃描時跳過損壞的數據塊.查看tablespace的空間使用情況
select a.tablespace_name,
trunc(sum(b.bytes/1024/1024),2) "FREE(M)",
trunc(sum(a.bytes/1024/1024)-sum(b.bytes/1024/1024),2) "USED(M)",
trunc(sum(a.bytes/1024/1024),2) "ALL(M)",
trunc(sum(b.bytes/1024/1024)/sum(a.bytes/1024/1024),2)*100'%' "Free(%)"
from dba_data_files a
join dba_free_space b
on(a.file_id=b.file_id)
group by a.tablespace_name;
如何指定tnsname.ora的位置
設置環境變量TNS_ADMIN獲取當前SCN(9i以後)
select dbms_Flashback.get_system_change_number from dual;
