ORA-06502: PL/SQL: numeric or value error: character string buffer too small

ERROR at line 1:
ORA-06502: PL/SQL: numeric or value error: character string buffer too small
ORA-06512: at “WMSYS.WM_CONCAT_IMPL”, line 30

DML error capture (捕获DML错误日志)

[oracle@orazhang ~]$ sqlplus anbob/anbob

fast delete, Best practice on Very large table

Today I read foreign blog,I think I learned the true knowledge
One of most operations we are performing is “Deleting many rows from oracle big tables” ;


maxrows number default 1000;
row_id_table dbms_sql.Urowid_Table;
currcount_table dbms_sql.number_Table;
cursor cur_t2 is….

trigger一点儿小发现new or :new、ORA-04091

If you delete the line “FOR EACH ROW” from the trigger, it becomes a statement trigger which is not subject to this restriction, and the trigger.

Backups to tape can only be backup sets. use rman

By default, RMAN creates all backups as backup sets, on tape or on disk. You can change the default backup type for disk backups to be image copies using the CONFIGURE command. Backups to tape can only be backup sets.


1,exp from a user,imp to b user,
2,impdp network_link,不生成dump文件直接导入

HWM 高水位储存位置

Extent Header:: spare1: 0 spare2: 0 #extents: 4 #blocks: 32
last map 0x00000000 #maps: 0 offset: 2716
Highwater:: 0x02400391 ext#: 3 blk#: 8 ext size: 8

Loss database default tablespace files affected and recovery



Any loss of controlfile effects of database and recovery the controlfile

Your database is having two control files, three redo log file groups with two members in each group. Failure of which file would cause an instance to shut down

loss of all controlfile,database is automatic shutdown abort?(丢失所有控制文件,数据库会关闭?)

Your database is configured in NOARCHIVELOG mode. All the control files have been lost due to a hard disk failure but the data files are not lost. You have the closed whole database backup available to you…


expdp with sys on linux

UDE-00008: operation generated ORACLE error 28009
ORA-28009: connection as SYS should be as SYSDBA or SYSOPER


recyclebin session on ,system off

SQL> show parameter recy NAME TYPE VALUE ————– […]

flashback DDL not affect

flashback query 可以闪回以前的数据行,但不可以闪回alter table修改前的表结构,这点在11G推出的闪回表空间是一样的…


One of the database users accidentally deleted all the rows of a critical table and committed the delete at 1:30 p.m. …

1z0-042 259题实验

Identify the two tablespaces whose data files are so critical that only a closed recovery is possible. (Choose two.)

windows配置oerr 查询oracle错误

在linux 上很容易查询 oracle的错误编码,得到提示、原因、及大概解决思路,但windows操作系统就没有办法应用oerr查询错误了,但是有群国外的哥们实现了在windows上使用oerr的方法

oracle10G 深入dual伪表(原)


sql 判断字段值是是否包含中文字符

从表里提取汉字, 需要考虑字符集, 不同的字符集汉字的编码有所不同
这里以GB2312为例, 写一函数准确地从表里提取简体汉字.


sqlplus 限制用户delete(product_user_profile) sp2-0544

SQL> delete test where id=1;
SP2-0544: Command “delete” disabled in Product User Profile