标签：rds startup lob 指定字段 重命名 创建 学习 div segment
1、不可见字段
SQL> create table ht (a number,b varchar2(20) invisible);
Table created.
SQL> desc ht;
Name Null? Type
----------------------------------------- -------- ----------------------------
A NUMBER
SQL> set colinvisible on
SQL> desc ht;
Name Null? Type
----------------------------------------- -------- ----------------------------
A NUMBER
B (INVISIBLE) VARCHAR2(20)
SQL> insert into ht values(1,‘beijing‘);
insert into ht values(1,‘beijing‘)
*
ERROR at line 1:
ORA-00913: too many values
SQL> insert into ht (a,b) values(1,‘beijing‘);
1 row created.
SQL> commit;
Commit complete.
SQL> select * from ht;
A
----------
1
SQL> select a,b from ht;
A B
---------- --------------------
1 beijing
SQL> insert into ht1 values(1,‘beijing‘);
1 row created.
不可见字段的表可以强制开发人员select 语句时指定字段不能用*代替,和普通表对比起来 插入数据时必须指定字段加大拉开发的代码量。
2、在同一列上创建不同功能索引
SQL> create index idx_ht_b1 on ht(b); Index created. SQL> create index idx_ht_b2 on ht(upper(b)); Index created.
3、ddl 语句日志记录
SQL> show parameter enable_ddl_logging; NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ enable_ddl_logging boolean TRUE SQL> create table ht2 as select * from ht1; Table created. SQL> drop table ht2 purge; Table dropped. [qdtais]@ht02[/u01/app/db/diag/rdbms/qdtais/qdtais/log/ddl]$tail -10 log.xml <txt>create table ht2 as select * from ht1 </txt> </msg> <msg time=‘2019-12-05T18:27:42.271-05:00‘ org_id=‘oracle‘ comp_id=‘rdbms‘ msg_id=‘opiexe:4850:2946163730‘ type=‘UNKNOWN‘ group=‘diag_adl‘ level=‘16‘ host_id=‘ht02‘ host_addr=‘fe80::f9f1:ad02:b6a6:ea2f%enp0s3‘ pid=‘4338‘> <txt>drop table ht2 purge </txt> </msg>
4、dba保护增强--备份可以分配权限
SQL> grant sysbackup to ht; Grant succeeded. SQL> exit Disconnected from Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production Version 19.3.0.0.0 [qdtais]@ht02[/home/oracle]$rman target ht/ht Recovery Manager: Release 19.0.0.0.0 - Production on Thu Dec 5 18:36:46 2019 Version 19.3.0.0.0 Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved. connected to target database: QDTAIS (DBID=1154019395) RMAN>
5、expdp/impdp 增强
impdp 避免产生大量日志 TRANSFORM Metadata transform to apply to applicable objects. Valid keywords are: DISABLE_ARCHIVE_LOGGING, INMEMORY, INMEMORY_CLAUSE, LOB_STORAGE, OID, PCTSPACE, SEGMENT_ATTRIBUTES, SEGMENT_CREATION, STORAGE, and TABLE_COMPRESSION_CLAUSE. expdp时把视图转化为表 VIEWS_AS_TABLES Identifies one or more views to be exported as tables. For example, VIEWS_AS_TABLES=HR.EMP_DETAILS_VIEW
6、varchar2 nvarchar2 数据字段长度扩大到32K，11g以前只有4K，存大文本时避免使用 clob blob,数据库需要重启。
SQL> show parameter max_string_size;
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
max_string_size string STANDARD
SQL> ALTER SYSTEM SET max_string_size=extended SCOPE=SPFILE;
System altered.
SQL> startup upgrade
ORACLE instance started.
Total System Global Area 1644163728 bytes
Fixed Size 8897168 bytes
Variable Size 637534208 bytes
Database Buffers 989855744 bytes
Redo Buffers 7876608 bytes
Database mounted.
Database opened.
SQL> @?/rdbms/admin/utl32k.sql
7、 在线移动并重命名数据文件,move数据文件时不影响用户ddl、dml，可以把omf文件转化为正常文件，也可以直接move到asm磁盘组
FILE# NAME
---------- --------------------------------------------------------------------------------
1 /u01/app/db/oradata/QDTAIS/system01.dbf
3 /u01/app/db/oradata/QDTAIS/sysaux01.dbf
4 /u01/app/db/oradata/QDTAIS/undotbs01.dbf
5 /u01/app/db/oradata/QDTAIS/datafile/o1_mf_ht_gym38cqq_.dbf
7 /u01/app/db/oradata/QDTAIS/users01.dbf
SQL> alter database move datafile 5 to ‘/home/oracle/o1_mf_ht_gym38cqq_.dbf‘;
alter database move datafile 5 to ‘/home/oracle/o1_mf_ht_gym38cqq_.dbf‘
*
ERROR at line 1:
ORA-01276: Cannot add file /home/oracle/o1_mf_ht_gym38cqq_.dbf. File has an Oracle Managed Files file name.
SQL> alter database move datafile 5 to ‘/home/oracle/*‘;
Database altered.
SQL> alter database move datafile 5 to ‘/u01/app/db/oradata/QDTAIS/ht01.dbf‘;
Database altered.
SQL> select file#,name from v$datafile;
FILE# NAME
---------- --------------------------------------------------------------------------------
1 /u01/app/db/oradata/QDTAIS/system01.dbf
3 /u01/app/db/oradata/QDTAIS/sysaux01.dbf
4 /home/oracle/undotbs01.dbf
5 /u01/app/db/oradata/QDTAIS/ht01.dbf
7 /u01/app/db/oradata/QDTAIS/users01.dbf
8、高级索引压缩及表压缩，以前这些特性只在oracle亲儿子exadata上使用
SQL> SELECT table_name, compression, compress_for FROM user_tables; TABLE_NAME COMPRESSION COMPRESS_FOR ---------------- ------------ ----------------- T1 DISABLED T2 ENABLED BASIC T3 ENABLED ADVANCED T4 ENABLED QUERY HIGH T5 ENABLED ARCHIVE LOW
标签：rds startup lob 指定字段 重命名 创建 学习 div segment
原文地址：https://www.cnblogs.com/omsql/p/11993133.html
