Oracle参数篇
1. ARCHIVE_LAG_TARGET forces a log switch after the specified amount of time elapses.有效值为0(disabled)或 [ 60,7200 ]
2. SEC_PROTOCOL_ERROR_FURTHER_ACTION specifies the further execution of a server process when receiving bad packets from a possibly malicious client.SEC_PROTOCOL_ERROR_FURTHER_ACTION = { CONTINUE | (DELAY,
integer
) | (DROP,
integer
) }
3. ASM_POWER_LIMIT specifies the maximum power on an Automatic Storage Management instance for disk rebalancing. The higher the limit, the faster rebalancing will complete. Lower values will take longer, but consume fewer processing and I/O resources.
4. DB_FILE_MULTIBLOCK_READ_COUNT DB_FILE_MULTIBLOCK_READ_COUNT
is one of the parameters you can use to minimize I/O during table scans. It specifies the maximum number of blocks read in one I/O operation during a sequential scan. The total number of I/Os needed to perform a full table scan depends on such factors as the size of the table, the multiblock read count, and whether parallel execution is being utilized for the operation.
5. SGA_MAX_SIZE SGA_MAX_SIZE
specifies the maximum size of the SGA for the lifetime of the instance.On 64-bit platforms and non-Windows 32-bit platforms, when either MEMORY_TARGET
or MEMORY_MAX_TARGET
is specified, the default value of SGA_MAX_SIZE
is set to the larger of the two parameters. This causes more address space to be reserved for expansion of the SGA.
6. OPEN_CURSORS OPEN_CURSORS
specifies the maximum number of open cursors (handles to private SQL areas) a session can have at once. You can use this parameter to prevent a session from opening an excessive number of cursors.
7. DB_FLASHBACK_RETENTION_TARGET DB_FLASHBACK_RETENTION_TARGET
specifies the upper limit (in minutes) on how far back in time the database may be flashed back. How far back one can flashback a database depends on how much flashback data Oracle has kept in the fast recovery area.
8. LOCAL_LISTENER LOCAL_LISTENER
specifies a network name that resolves to an address or address list of Oracle Net local listeners (that is, listeners that are running on the same machine as this instance). The address or address list is specified in the TNSNAMES.ORA
file or other address repository as configured for your system.语法:LOCAL_LISTENER =
network_name,默认值是
(ADDRESS = (PROTOCOL=TCP)(HOST=
hostname
)(PORT=1521))
where hostname
is the network name of the local host.
它填的是TNSNAMES.ORA中的网络字符串,通过该网络字符串来映射本地监听器的地址,若TNSNAMES.ORA文件中内容如下:
TEST3 = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = node2.being.com)(PORT = 1523)) ) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = sz.being.com) ) ) TEST2 = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = node2.being.com)(PORT = 1522)) ) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = sz.being.com) ) ) TEST1 = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = node2.being.com)(PORT = 1521)) ) (CONNECT_DATA = (SERVER = DEDICATED) (SERVICE_NAME = sz.being.com) ) )
倘若两个端口1522,1523对应的监听器已启动,若我将LOCAL_LISTENER设置为以下值:SQL> alter system set local_listener='TEST3';则我用TEST2登陆数据库,会报以下错误:
[oracle@node2 admin]$ sqlplus scott/tiger@test2 ERROR: ORA-12514: TNS:listener does not currently know of service requested in connect descriptor Enter user-name:
但是用TEST3,即sqlplus scott/tiger@test3会成功登陆,反之亦然。
如果我想既能用TEST2登陆又能用TEST3登陆,则LOCAL_LISTENER必须设置为以下值:SQL> alter system set local_listener='TEST2','TEST3';
注意:1. 若LOCAL_LISTENER为空,则默认映射1521端口
2. 即便LOCAL_LISTENER设置为 local_listener='TEST2','TEST3',TEST1仍能成功登陆,即1521端口是默认的。
相关文章
- java 实现往oracle存储过程中传递array数组类型的参数
- oracle中的表空间以及和表空间有关的操作
- oracle参数文件与启动过程
- oracle 迁移数据文件
- Oracle 修改参数
- Oracle 数据库 Only 导出空表的方法
- Oracle 数据表误删恢复 Flashback
- PDB自动启动以及Oracle Pfile的参数修改示范
- Oracle 测试环境 数据库安装过程
- Oracle:dba_hist_seg_stat_obj 字典表 初步研究
- Oracle 12c Windows安装、介绍及简单使用(图文)
- oracle to_char FM099999
- Oracle左连接、右连接、全外连接以及(+)号用法
- 深入解析Oracle 10g中SGA_MAX_SIZE和SGA_TARGET参数的区别和作用
- Oracle 内存参数调优设置
- Oracle 查看表空间的大小及使用情况sql语句
- 查看oracle数据库的大小和空间使用情况
- Oracle 11g RAC to RAC ADG搭建(一)采用rman备份恢复方式
- [Oracle]Oracle数据库任何用户密码都能以sysdba角色登入
- Oracle Patchset 不同文件的作用