oracle11g Expdp COMPRESSION(数据泵压缩增强)


oracle11g add default values columns(增加默认值列的改进)

oracle 11G 对 现有表增加指定默认值列方式发生了很大变化,无论是存储方式上,还是效率上,下面看一个简单的实验




BLOB select、insert、exp with sqlplus

SQL> create table testblob(id int,comm blob);

Table created.

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….

sql server 备份文件ftp批处理

sql server 的维护计划可以定期的备份与删除备份文件,下面只提供备份文件从OS角度的处理方法,如何压缩传ftp,及删除过期的压缩文件


2011年7月21日 5:22,是对于我及家人来说非常重要的时刻,因为我的女儿出生了…


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…